JP3865681B2 - Brush writing device, brush writing program, and brush writing method - Google Patents

Description

なお、この計算式で使用する筆圧最大時の筆の長さ（Ｌ１）、根元の幅（Ｗ２）、筆先の幅（Ｗ１）を可変パラメータとして自由に筆の初期サイズ（大筆、中筆、小筆）を変更できるようにしてもよい。
【００６２】
上式では、筆圧が大きくなるほど筆先が広がっていく描画モデルとしたが、筆先形状が筆圧に依存しない描画モデルを採用してもよい（図６（ｃ）参照）。この場合には、書きはじめや細字の描画が太く不自然とならないように筆先の閉じた描画パタンを使用することが好ましい。
【００６３】
圧力検知部５０３は、たとえば、タブレット１５０と、ドライバソフト４４３などによりその機能を実現することができる。描画パタン拡大縮小部５０４は、たとえば、ＣＰＵ４０１と、ＲＡＭ４０３と、毛筆ソフト４４２などによりその機能を実現することができる。
【００６４】
移動方向算出部５０５は、座標値検出部５０２で順次検出された座標値に基づいてタブレットペン１０３の移動方向を算出する。描画パタン回転部５０６は、移動方向算出部５０５で算出された移動方向の反対方向に描画パタンの筆先部分が向くように描画パタンを回転させる。毛筆描画装置１００では、タブレット板１０２のサンプリング点（順次検出される座標値）に対応させて描画パタンを描画すると共に、サンプリング点の間を補間することにより毛筆描画をおこなうが、描画パタン回転部５０６は、各サンプリング点で、筆の進行方向に従って筆先の向きを変える処理をおこなう。
【００６５】
このときの処理として、まず、タブレットペン１０３を降ろした際の筆先初期角度を決定する必要がある。毛筆描画装置１００では、タブレットペン１０３が座標入力を開始した位置（タブレット板１０２に接触した位置）から、一定以上の距離を移動するまでのサンプリング点をスキップし、一定の距離を超えたところの座標値と入力開始時の座標値とからタブレットペン１０３の進行方向を求め、この方向に応じて描画パタンの向き（初期角度）を計算する方法を採用している。
【００６６】
これは、筆の着紙前後では手ぶれが発生しやすく、たとえばタブレットペン１０３が降ろされる直前のサンプリング点と、タブレットペン１０３がタブレット板１０２に触れた（座標入力を開始した）ときのサンプリング点から筆の進行方向を求め初期角度を計算すると、筆の移動量も小さく演算誤差が非常に大きくなるからである。なお、初期角度を決定するためのタブレットペン１０３の移動距離のしきい値としては、描画パタンの最大長Ｌ１の４分の１とすることができる（図７参照）。
【００６７】
移動方向算出部５０５と描画パタン回転部５０６は、初期角度の決定後、順次各サンプリング点を結ぶ直線の向きを求め、描画パタンの筆先を回転する。直前のタブレットペン１０３の位置を（ｘ_ｉ−１，ｙ_ｉ−１）、現在の位置を（ｘ_ｉ，ｙ_ｉ）とすると、描画パタンの向きθは
θ＝Ｔａｎ^−１（−（ｙ_ｉ−ｙ_ｉ−１）／（ｘ_ｉ−ｘ_ｉ−１）） ・・・式（１）
となる。なお、図８に、描画パタンの向きθとタブレットペンの移動方向の関係を示す。
【００６８】
移動方向算出部５０５は、たとえば、ドライバソフト４４３と、ＲＡＭ４０３と、ＣＰＵ４０１と、毛筆描画ソフト４４２などによりその機能を実現することができる。描画パタン回転部５０６は、たとえば、ＲＡＭ４０３と、ＣＰＵ４０１と毛筆描画ソフト４４２などによりその機能を実現することができる。
【００６９】
距離間隔算出部５０７は、座標値検出部５０２で順次検出された座標値の隣り合う距離間隔を算出する。また、回転制御部５０８は、距離間隔算出部５０７で算出された座標値の距離間隔に基づいて、描画パタン回転部５０６を制御し、描画パタンの回転量を小さくする。すなわち、回転制御部５０８では、カド部分における「慣性」を考慮した描画を実現する。換言すれば、カド部分での不自然な突起描画を防止する。
【００７０】
現実の毛筆描画を詳細に観察すると、実際には、カド部分では、摩擦などの要因により筆の向きは急激に変化せず、少し遅れて緩やかに変化する。毛筆描画装置１００は、このような特性を表現するため「慣性」というパラメータを設け、筆の向き（描画パタンの回転）の変化度合いを自由に調整できるようにしている。なおタブレットペン１０３を降ろしたときの初期角度以外は、この慣性パラメータによって筆の向きの変化量を調整するようにする。
【００７１】
毛筆描画装置１００で慣性を用いて描画をおこなう場合、回転制御部５０８は、回転角度θ‘_ｉを次式により計算する。
θ‘_ｉ ＝ θ‘_ｉ−１ ＋ （１００−ｍ）・Δθ_ｉ ／ １００ ・・・式（２）
Δθ_ｉ ＝ θ_ｉ−θ‘_ｉ−１ （−π＜Δθ_ｉ≦π）
ここで、
θ‘_ｉ−１ サンプリング点ｉ−１における回転角度（慣性あり）
θ_ｉ 移動方向算出部５０５で求めたサンプリング点ｉにおけるタブレットペン１０３の移動方向の反対方向（慣性なし）
Δθ_ｉ サンプリング点ｉ−１における回転角度の変化量（−π〜π）
ｍ 慣性（０〜１００）
なお、θ‘_ｉ−１は着紙直後（座標入力の開始直後）では前述した初期角度を使用し、それ以外では直前のサンプリング点で式（２）により計算した回転角度を使用する。Δθ_ｉは、−π〜πの範囲に正規化した角度を使用する。
【００７２】
式（２）から明らかなように、慣性ｍの値が大きいほど回転が緩やかになる。ｍ＝１００の場合は全く回転せず（θ‘_ｉ ＝θ‘_ｉ−１）、ｍ＝１００の場合はタブレットペン１０３の進行方向の反対向きθ‘_ｉ＝θ_ｉとなる。
【００７３】
以上は、慣性ｍを用いた描画パタンの向きの決定する処理であるが、毛筆描画装置１００では、この慣性ｍをタブレットペン１０３の移動速度に応じて変化させる。これにより、単に座標値検出部５０２で検出された位置に描画パタンを順次重ね合わせて描画していく場合に、文字の折り返し部分で生じる不自然な突起を防ぐことができる。図９は、カドにおける不自然な突起描画と、慣性を制御した場合の描画パタンの向きを示した描画概念図である。このうち、図９（ａ）は、慣性を考慮しない描画図であり、図９（ｂ）は、図９（ａ）で示した描画についてカド部分前後の描画パタンの配向を示した図であり、図９（ｃ）は、慣性を考慮した描画パタンの配向を示した図である。
【００７４】
不自然な突起は、特に、ゆっくりとペンを動かした場合に、ペンが下方に下がりきらないうちに描画パタンが回転してしまうことに起因する。回転制御部５０８は、タブレットペン１０３の移動速度が遅いときに慣性ｍが高くなるように回転制御する。回転制御はたとえば以下の式を採用することができる。
ｍ’ _ｉ ＝ ＭＡＸ（１００−ｒｆ_ｉ， ｍ）
ｒｆ_ｉ ＝ （Ｄ_ｉ ^２・α） ／ （ ＭＡＸ（ｌ１_ｉ ， ｌ１_ｉ−１） ＋ １ ） ＋ β
（但し、Ｄ_ｉ＝０の場合はｒｆ_ｉ＝０）
Ｄ_ｉ ^２ ＝ （ｘ_ｉ−ｘ_ｉ−１）^２ ＋ （ｙ_ｉ−ｙ_ｉ−１）^２
ここで、
ｍ’ _ｉ サンプリング点ｉにおける補正済みの慣性値（０〜１００）
ｍ 補正前の慣性値（０〜１００）（下限値として使用）
ｒｆ_ｉ サンプリング点ｉにおける回転係数
Ｄ_ｉ サンプリング点ｉとサンプリング点ｉ−１との距離
ｌ１_ｉ サンプリング点ｉにおける描画パタンの長さ
ｌ１_ｉ−１ サンプリング点ｉ−１における描画パタンの長さ
α，β 微調整のための定数（例えばα＝１０、β＝３）
ｘ_ｉ， ｙ_ｉ サンプリング点ｉの座標値
ｘ_ｉ−１， ｙ_ｉ−１ サンプリング点ｉ−１の座標値
なお、座標は整数値で管理するものとする。
従って、最終的な回転角度θ‘_ｉは下式となる。
θ‘_ｉ ＝ θ‘_ｉ−１ ＋ （１００−ｍ’ _ｉ）・Δθ_ｉ ／ １００ ・・・式（３）
【００７５】
以上のようにタブレットペン１０３の移動速度に従って慣性値ｍを変化させながら描画をおこなうことにより、カドの部分での不自然な突起描画が抑制される。また、カドの部分に限らず、ペンをゆっくり移動させた場合には手ぶれや演算誤差の増大によって線の途中に不自然な盛り上がりが生じうるが、この現象についても同時に解消される。距離間隔算出部５０７は、たとえば、毛筆描画ソフト４４２と、ＲＡＭ４０３と、ＣＰＵ４０１などによりその機能を実現することができる。回転制御部５０８は、たとえば、毛筆描画ソフト４４２と、ＲＡＭ４０３と、ＣＰＵ４０１などによりその機能を実現することができる。
【００７６】
転回判定部５０９は、移動方向算出部５０５で算出された移動方向が急転回したか否かを判定する。また、描画パタン短縮部５１０は、転回判定部５０９で移動方向が急転回したと判定された場合に、所定の描画個数分または所定の描画距離分だけ描画パタンの長さを短くする。折り返しのような１８０度に近い大幅な方向転換を行った場合には、慣性を考慮しても不自然な突起が描かれる場合があり（図１０参照）、描画パタン短縮部５１０は、この突起描画を防止する。
【００７７】
現実の毛筆描画を詳細に観察すると、実際には、折り返し部分では、筆先が裏返えることにより綺麗な描画が実現されている。毛筆描画装置１００は、筆先の裏返りをシミュレートすることにより、この問題に対処している。具体的には、まず、筆先の裏返りを判定するために、各サンプリング点において筆先回転率ｒｒ_ｉを計算する
ｒｒ_ｉ ＝ ｜Δθ_ｉ｜・１００ ／ π ・・・式（４）
Δθ_ｉ ＝ θ_ｉ−θ‘_ｉ−１ （−π＜Δθ_ｉ≦π）
ここで、
ｒｒ_ｉ サンプリング点ｉにおける筆先回転率
θ‘_ｉ−１ 式（３）により求めたサンプリング点ｉ−１における回転角度（慣性あり）
θ_ｉ 式（１）により求めたサンプリング点ｉにおける回転角度（慣性なし）
Δθ_ｉ サンプリング点ｉ−１における回転角度の変化量（−π〜π）
【００７８】
転回判定部５０９は、式（４）により計算した筆先回転率ｒｒ_ｉが一定値以上の場合に筆先が裏返った、すなわち、移動方向が急転回したと判断する。この一定値は、たとえば、８０とすることができる。毛筆描画装置１００は、筆先が裏返ったと判定した場合は筆先反転フラグをセットし、そのサンプリング点での座標値（ｔｘ，ｔｙ） を保存し、回転角度をθ‘_ｉ−１＝θ_ｉ、θ‘_ｉ＝θ_ｉとして描画をおこなう。
【００７９】
描画パタン短縮部５１０は、筆先反転フラグがセットされているときは、一時的に筆先の長さを短くした描画パタンを採用する。筆先の長さｌ１_ｉ‘としては、たとえば、下式により計算することができる。
ｌ１_ｉ’ ＝ Ｄｔ_ｉ・（ｌ１_ｉ−ｗ２_ｉ） ／ Ｌ１ ＋ ｗ２_ｉ （丸筆の場合）
ｌ１_ｉ’ ＝ Ｄｔ_ｉ・ｌ１_ｉ ／ Ｌ１ （平筆の場合）
Ｄｔ_ｉ ＝ ｓｑｒｔ（（ｘ_ｉ−ｔ_ｘ）^２＋（ｙ_ｉ−ｔ_ｙ）^２）
但し、Ｄｔ_ｉ＞Ｌ１の場合はＤｔ_ｉ＝Ｌ１
ここで、
Ｄｔ_ｉ サンプリング点ｉの折り返り点からの距離
ｘ_ｉ， ｙ_ｉ サンプリング点ｉの座標値
ｔｘ，ｔｙ 折り返り点の座標値
ｗ２_ｉ サンプリング点ｉでの描画パタンの根元部分の幅
ｌ１_ｉ サンプリング点ｉにおける描画パタンの長さ
Ｌ１ 描画パタンの最大長
なお、サンプリング点ｉの折り返り点からの距離Ｄｔ_ｉは下記の式により近似してもよい。
Ｄｔ_ｉ ＝ ｜ｘ_ｉ−ｔｘ｜ ＋ ｜ｙ_ｉ−ｔｙ｜ 但し、Ｄｔ_ｉ＞Ｌ１の場合はＤｔ_ｉ＝Ｌ１
【００８０】
転回判定部５０９は、Ｄｔ_ｉ≧Ｌ１となった時点で筆先反転フラグをクリアする処理をおこなう。このように、筆先が裏返ったと判断された場合、一時的に筆先の長さを短く補正して円に近い描画パタンで描画をおこなうことにより、筆先の裏返りをシミュレートし、大幅な方向転換を行った場合すなわち折り返し点での描画の不具合を解消することができる。
【００８１】
転回判定部５０９は、たとえば、毛筆描画ソフト４４２と、ＲＡＭ４０３と、ＣＰＵ４０１などによりその機能を実現することができる。なお、タブレットペン１０３が座標入力面１２１に対する傾きを検出する傾き検出機能を備えている場合には、タブレットペン１０３も転回判定部５０９の機能的構成要素となる。描画パタン短縮部５１０は、たとえば、毛筆描画ソフト４４２と、ＲＡＭ４０３と、ＣＰＵ４０１などによりその機能を実現することができる。
【００８２】
描画部５１１は、描画パタン回転部５０６または回転制御部５０８で回転され、描画パタン拡大縮小部５０４で拡大または縮小され、描画パタン短縮部５１０で長さを短くされた描画パタンを、座標値検出部５０２で検出された座標位置に順次描画する。なお、描画にあたっては、各サンプリング点の間に補間用の描画パタンを描画することにより、間の隙間を埋める処理をおこなう。このとき、単に、相似形の描画パタンを使用して描画をおこなう場合には、各サンプリング点を結ぶ直線を構成する点の位置に描画パタンのホットスポットが重なるように補間パタンを描画していけばよい。しかしながら、毛筆描画装置１００で採用する描画モデルは、筆圧や筆の進行方向によって描画パタンの形状が変化するため、筆先がサンプリング点間を結ぶ直線よりも長い軌跡を描く場合があり、単純な補間処理では、所々隙間があいてしまい、滑らかに補間することができない。
【００８３】
従って、描画部は、各サンプリング点での描画パタンを形成する多角形の頂点同士を結ぶ直線の中で最長の直線の長さを基に補間点数を求め、各補間点において筆圧と進行方向を徐々に変化させてできた描画パタンを描画していく処理もおこなう。
【００８４】
丸筆の場合は、筆の根元部分を示す円周上の真中にあたる点同士と、筆先を示す台形の各頂点間同士の直線距離を求め、平筆の場合は、筆先を示す台形の各頂点間同士の直線距離を求める。これらの頂点間同士で距離の一番長い直線の長さから補間点数を求める。具体的には、基準直線の始端座標を（ｘ１， ｙ１）、終端座標を（ｘ２， ｙ２）とすると、｜ｘ２−ｘ１｜≧｜ｙ２−ｙ１｜の場合は補間点数を｜ｘ２−ｘ１｜とし、｜ｘ２−ｘ１｜＜｜ｙ２−ｙ１｜の場合は補間点数を｜ｙ２−ｙ１｜とする。なお、座標値は整数値とする。
【００８５】
描画部５１１は、このようにして求めた補間点数により、各補間点の座標を計算し、各補間点での描画パタンのホットスポットが各サンプリング点を結ぶ直線上をたどるように描画していく。なお、描画パタンの各頂点を結ぶ線の軌跡は現実の描画では曲線を描くことになるため、補間点数を１．２〜１．５倍した補間点数を使用してもよい。補間中の筆圧、回転角度など変数の変化量は、補間をおこなう２点間での各変数の差分を補間数で割ったものを使用する。
【００８６】
毛筆描画装置１００は、描画部５１１の描画処理により質感の高い毛筆描画を可能とする。描画部５１１は、たとえば、毛筆描画ソフト４４２と、ＲＡＭ４０３と、ＣＰＵ４０１と、グラフィックスカード４０５と、表示装置１０４などによりその機能を実現することができる。
【００８７】
（毛筆描画装置１００の機能的構成：描画パタン自体の表現に関する機能的構成）
つぎに、毛筆描画装置１００の機能的構成のうち、特に描画パタン自体の表現に関する機能的構成について説明する。現実の毛筆描画では、毛筆を構成する毛の束や、墨汁の量、墨汁のにじみ易さ分離し易さなどの複数の要因が絡み合って毛筆独特の描画質感（かすれ、にじみ）を形成する。毛筆描画装置１００では、この描画質感を描画パタンの内部画像を変化させることにより表現する。
【００８８】
図１１は、本実施の形態の毛筆描画装置のうち描画パタンの内部画像を変化させる機能的構成の一例を示した説明図である。毛筆描画装置１００は、描画パタン内の表現を変化させる機能的構成として、濃淡画像調整部５１２と、停留判定部５１３と、平滑化部５１４と、停留回数計数部５１５と、平滑化制御部５１６と、を有する。ここではまず、描画パタン内部の一般的な濃淡画像について説明し、続いて各機能的構成について説明する。
【００８９】
図１２は、毛筆描画装置１００で採用する描画パタンと描画パタン内部の濃淡画像の一例を示した図である。濃淡や隙間のあいた描画パタンを用いることによって、毛筆１本１本の軌跡を反映した質感の高い描画が可能となる。描画パタンの生成方法としては、たとえば、中心から離れるにつれて徐々に薄くなっていく点パタンをランダムに描画パタン内に振る方法が挙げられる。具体的には、次のような点パタンを用いることができる。
Ｐ_ｘｙ ＝ ａ・Ｄ_ｘｙ ^２ （０≦Ｐ_ｘｙ≦２５５）
（但し、Ｐ_ｘｙ＞２５５の場合はＰ_ｘｙ ＝２５５）
ここで、
Ｐ_ｘｙ ピクセルの輝度（色値）
Ｄ_ｘｙ 中心点とそのピクセルとの距離
ａ 広がりを調整するための係数
描画パタンは、点パタンの係数ａの値を調整することで、隙間の量を調整可能としている。
【００９０】
描画パタンの生成方法は、これ以外にも、たとえば、乱数により適当な個数のランダムな点を生成し、描画モードに応じて平滑化フィルタでこの点をぼかし、描画パタンが薄くならないように輝度レベルの補正を行って得てもよい。
【００９１】
なお、平滑化フィルタは、ある中心ピクセル（注目画素）と近傍のピクセルに注目し、指定された隣接範囲の色を平均化するという処理フィルタである。なお、矩形のフィルタを使用すると、四角いボケ方をするので、注目画素からの距離によって異なる重みをつけて、丸いボケ方をするようにしてもよい。
【００９２】
以降では、点パタンや平滑化フィルタを施され、ぼかしやボケの入った単位画像を濃淡画像と称することする。濃淡画像を調整することにより、毛筆独特のかすれやにじみを質感良く再現できる。
【００９３】
まず、かすれを表現可能とする機能部について説明する。濃淡画像調整部５１２は、圧力検知部５０３で検出された圧力と距離間隔算出部５０７で判定された座標値の距離間隔に従って、濃淡画像の個数と大きさと濃淡を調整する。なお、使用の態様によっては、圧力のみに依存させる態様であってもよいし、距離間隔のみに依存させる態様であってもよい。また、個数のみを調整する態様であってもよいし大きさのみを調整する態様であってもよいし濃淡のみを調整する態様であってもよい。また、個数、大きさ、濃淡のうち２つを調整する態様であってもよい。
【００９４】
毛筆描画装置１００では、計算処理負担を軽減するため、たとえば、点のサイズを大中小と３段階に限定し、輝度レベル補正の際のパラメータ調整を併用することにより、見かけ上連続的に隙間の量を調整できるようにしている。濃淡画像の調整は、描画モード選択時の初期段階に決定し、描画中に動的に変化させるものとする。濃淡画像調整部５１２による調整により、筆圧やタブレットペン１０３の速度によって自動的に隙間量を増減させることが可能となる。これにより、質感の高いかすれ表現が可能となる。濃淡画像調整部５１２は、たとえば、毛筆描画ソフト４４２と、ＲＡＭ４０３と、ＣＰＵ４０１などによりその機能を実現することができる。
【００９５】
つぎに、にじみを表現する機能部について説明する。停留判定部５１３は、座標値検出部５０２で検出された座標値に基づいてタブレットペン１０３が停留しているか否かを判定する。平滑化部５１４は、停留判定部５１３でタブレットペン１０３が停留していると判断された場合に、描画パタンに平滑化処理を施す。停留回数計数部５１５は、停留判定部５１３でタブレットペン１０３が同一場所に停留していると判定された回数を計数する。平滑化制御部５１６は、停留回数計数部５１５で計数された回数に従って、平滑化部５１４を制御して平滑化処理の拡散パラメータを大きくする。
【００９６】
現実の毛筆描画では、墨と水が分離しやすいような墨汁（例えば薄い墨）を筆に充分染み込ませて描画した場合に、特に停留点でにじみが見られる。毛筆描画装置１００では、タブレットペン１０３の停留時に停留時間に従って、拡散係数を大きくした平滑化フィルタを描画パタンに施し描画することにより、にじみを質感高く表現可能としている。にじみの再現については平滑化処理を採用するが、このとき、輝度補正をしないことにより、徐々に濃度が淡くなる様子を簡便に表現可能となる。図１３は、描画パタンに平滑化処理を順次施し、にじみが伝播する様子を示した図である。なお、徐々に拡散係数を増やしていく代わりに、前回使用した描画パタンを記憶しておき、それに重ねて平滑化処理を行った描画パタンを使用することによってもにじみの伝播を表現できる。
【００９７】
平滑化部５１４と平滑化制御部５１６は、たとえば、毛筆描画ソフト４４２と、ＲＡＭ４０３と、ＣＰＵ４０１などによりその機能を実現することができる。停留回数計数部５１５は、たとえば、タブレット板１０２と、ドライバソフト４４３と毛筆描画ソフト４４２などによりその機能を実現することができる。
【００９８】
描画部５１１は、描画パタン内の濃淡画像を変化させるこれらの各機能部の処理を経て決定ないし調整された描画パタンを、順次タブレットペン１０３の入力した座標位置に描画する。なお、毛筆描画装置１００は、墨汁を使った毛筆書画を表示装置１０４に質感高く再現するが、このほか、同様のアルゴリズムを用いて水彩筆や油彩筆による描画を再現することができる。特に、油彩筆を再現する場合には描画パタンにエンボスフィルタを施し、陰影をつけてもよい。図１４は、陰影パタンと描画例を示した図である。このうち、図１４（ａ）は、処理前の描画パタンであり、図１４（ｂ）は、エンボスフィルタを施した後の描画パタンであり、図１４（ｃ）は、描画例を示している。
【００９９】
（毛筆描画装置１００の描画サンプル）
つぎに毛筆描画装置１００の描画例を示す。図１５は、毛筆描画装置の描画例を示した図である。図示したように、「とめ」「はね」「はらい」「かえし」など、現実の毛筆描画と同等の描画表現が可能となっていることが分かる。特に、タブレットペン１０３が座標の入力を開始したところと、座標の入力が終了したところの質感が極めて良く再現されていることが確認できる。
【０１００】
図１６は、各種の描画モードによる毛筆描画例を示した図である。図１７は、図１６に示した各種の描画モードのパラメータを表示した図表である。図示したように、丸筆では、普通筆、ベタ筆、渇筆、薄墨筆の各描画モードを表現し、平筆では、水彩筆や油彩筆の描画モードを表現している。パラメータを適切に設定することにより、各種の描画表現が可能となっていることが分かる。
【０１０１】
毛筆描画装置１００は、消しゴムモードも備える。消しゴムモードとは、タブレットペン１０３の消しゴム部１３２が座標入力面１２１に座標を入力しているときに、その軌跡に沿って、なぞられた部分の線画を消去するモードをいう。消しゴムモードにより、コンピュータシステムのアンドゥー機能とはまた異なる描画質感を実現できる。なお、消しゴムモードは、タブレットペン１０３と連動しているので、従来のように複数回のアイコンクリックやプルダウン選択などにより実現されていた消しゴムモード選択のような煩雑さを解消し、毛筆描画装置１００の操作性を向上させることが可能となる。
【０１０２】
（毛筆描画装置の処理流れ）
つぎに、毛筆描画装置１００の処理流れについて説明する。図１８は、毛筆描画装置１００の処理流れの一例について説明したフローチャートである。毛筆描画装置１００は、まず、描画モードを決定する（ステップＳ６０１）。具体的には、描画パタンと描画パタンの描画中の制御パラメータを決定する（図１７参照）。
【０１０３】
続いて、タブレットペン１０３が入力している座標の座標値を所定の時間間隔毎に検出すると共に、座標を入力しているときの圧力を検知する（ステップＳ６０２）。毛筆描画装置１００では、タブレット１５０を用いているので、タブレット１５０により座標および圧力に関する情報を検知することができる。つぎに、座標値の軌跡からタブレットペン１０３の移動方向を算出し、描画パタンの配向（筆先方向）を決定する（ステップＳ６０３）。決定に際しては、タブレットペン１０３の移動方向の正反対の方向にむけて所定の慣性をもって配向する。具体的には、タブレットペン１０３の移動速度が小さくなるに従って回転角度の回転量を小さくする処理をおこなう。
【０１０４】
続いて、入力された座標の方向が急転回したかを判定し（ステップＳ６０４）、急転回したと判定された場合には、描画パタンの長さ部分を小さくする処理をおこなう（ステップＳ６０５）。ステップＳ６０３、ステップＳ６０４およびステップＳ６０５を経ることにより、描画している文字のカド部分や折り返し部分に不自然な突起が発現せず、自然な毛筆描画質感を得ることができる。
【０１０５】
最後に、各サンプリング点で順次描画パタンを描画していく（ステップＳ６０６）。サンプリング点上に描画していく描画パタンは、ステップＳ６０１で決定した描画モードの初期設定の画像に基づき、各種条件に従って適宜変化させる。具体的には、タブレットペン１０３の筆圧や速度に従って、描画パタンを構成する濃淡画像の個数や大きさや濃淡を調整する。特に、薄墨筆モードの場合はタブレットペン１０３の停留時間に従って平滑化処理を順次施し、墨滴がにじんでいくような描画パタンを描画する。
【０１０６】
なお、以上の各機能部はコンピュータプログラムとして実現できる。すなわち、コンピュータシステムを各機能部を実現させる手段として機能させることができる。図１９〜図２４は、コンピュータプログラムの処理結果を表示装置１０４に表示させた場合の画面構成例を示した図である。画面構成のうち、「ファイル」メニュー７０１は、ファイルのオープン、クローズ、新規作成などの基本動作をおこなうメニューである。また、「筆」メニュー７０２は、図１９〜図２４に示した各描画モード、消しゴムモード、および、後述するカスタム設定をおこなうメニューである。
【０１０７】
また、「背景」メニューは、下地を設定するメニューであり、たとえば、半紙（無地）、画用紙、キャンバス地を設定することができる。図２５は、画用紙の下地例を示した図であり、図２６は、キャンバス地の下地例を示した図である。図示したようにそれぞれの下地例では無地である半紙と異なる一定の濃淡画像が形成されており、描画パタンが重ね合わされることにより、下地を考慮した描画質感を得ることができる。現実の描画では、水彩画や油彩画で下地の凹凸が表にでる場合があるが、毛筆描画装置１００では、たとえば、キャンバス地に水墨画を描くなど、現実の組み合わせでは採用されない、コンピュータシステムならではの描画質感を得ることも可能となる。
【０１０８】
「色選択」メニュー７０４は、各種の描画色を選択するメニューである。従って、毛筆書画においては、黒以外の従来にない水墨画表現が可能となる。「消去」メニュー７０５は、描画画面７０６上に描画した文字や線図を総て消去するメニューである。
【０１０９】
つぎに、「筆」メニュー７０２の特性（Ｐ）について説明する。毛筆描画の各種パラメータのカスタム設定を可能にする。図２７は、描画パタンのサイズをカスタマイズする設定画面の一例を示した図である。図示したように、描画パタンの長さ、根元の幅、先端部の幅を変更可能としている。図２８は、濃淡画像などをカスタマイズする設定画面の一例を示した図である。図示したように、テクスチャパタンと描画パタンの合成比率、点密度の補正量、慣性ｍの調整、タブレットペン１０３の転回を判定する基準値を変更可能としている。なお、テクスチャパタンと描画パタンの合成比率とは、下地の凹凸や濃淡（テクスチャ）と描画パタンの濃淡の合成比率を表す。
【０１１０】
図２９は、インク（墨汁）をカスタマイズする設定画面の一例を示した図である。図示したように、インクの量、筆圧によるかすれの変化の有無、筆の早さによるかすれの変化の有無、速度によるかすれの量、にじみの量を変更可能としている。図３０は、濃度とコントラストをカスタマイズする設定画面の一例を示した図である。図３１は、染み込みの量と遅延制御をカスタマイズする設定画面の一例を示した図である。なお、遅延制御とは、パソコンの描画能力が低くて描画が追いつかない状態が発生したときに、自動的に補間を粗くし、ペンの動きに描画が追従しなくなるのを防止する機能を実現する制御をいう。
【０１１１】
以上説明した各機能部を適宜プログラム化し、タブレット１５０を備えるコンピュータシステムにインストールすることで、コンピュータを毛筆描画装置として作動させることができる。なお、プログラムの流通態様は、ＣＤ−ＲＯＭなどの記録媒体に限られずインターネットのような電気回線を通じて流通させることもできる。
【０１１２】
【発明の効果】
上記説明したように、本発明の毛筆描画装置（請求項１）は、描画する文字や線図の「カド」の部分で描画パタンが緩やかに方向転換し、加えて、簡便にかすれ表現が可能となり、これにより、タブレットを用いて自然な毛筆描画を質感良く再現可能となる。
【０１１３】
また、本発明の毛筆描画装置（請求項２）は、「はね」などのように、急峻な折り返し描画において、描画パタンによる不要な突起描画を防止し、これにより、タブレットを用いて自然な毛筆描画を質感良く再現可能となる。
【０１１４】
また、本発明の毛筆描画装置（請求項３）は、にじみ表現が可能となり、これにより、タブレットを用いて自然な毛筆描画を質感良く再現できる。
【０１１５】
また、本発明の毛筆描画装置（請求項４）は、「はね」などのように、急峻な折り返し描画において、描画パタンによる不要な突起描画を防止し、これにより、タブレットを用いて自然な毛筆描画を質感良く再現可能となる。
【０１１６】
また、本発明の毛筆描画装置（請求項５）は、動的なにじみ表現が可能となり、これにより、タブレットを用いて自然な毛筆描画を質感良く再現できる。
【０１１７】
また、本発明の毛筆描画プログラム（請求項６）は、描画する文字や線図の「カド」の部分で描画パタンが緩やかに方向転換し、加えて、簡便にかすれ表現が可能となり、これにより、タブレットを用いて自然な毛筆描画を質感良く再現可能となる。
【０１１８】
また、本発明の毛筆描画プログラム（請求項７）は、「はね」などのように、急峻な折り返し描画において、描画パタンによる不要な突起描画を防止し、これにより、タブレットを用いて自然な毛筆描画を質感良く再現可能となる。
【０１１９】
また、本発明の毛筆描画プログラム（請求項８）は、にじみ表現が可能となり、これにより、タブレットを用いて自然な毛筆描画を質感良く再現できる。
【０１２０】
また、本発明の毛筆描画プログラム（請求項９）は、「はね」などのように、急峻な折り返し描画において、描画パタンによる不要な突起描画を防止し、これにより、タブレットを用いて自然な毛筆描画を質感良く再現可能となる。
【０１２１】
また、本発明の毛筆描画プログラム（請求項１０）は、動的なにじみ表現が可能となり、これにより、タブレットを用いて自然な毛筆描画を質感良く再現できる。
【０１２２】
また、本発明の毛筆描画方法（請求項１１）は、にじみ表現が可能となり、これにより、タブレットを用いて自然な毛筆描画を質感良く再現できる。
【０１２３】
また、本発明の毛筆描画方法（請求項１２）は、「はね」などのように、急峻な折り返し描画において、描画パタンによる不要な突起描画を防止し、これにより、タブレットを用いて自然な毛筆描画を質感良く再現可能となる。
【０１２４】
また、本発明の毛筆描画方法（請求項１３）は、動的なにじみ表現が可能となり、これにより、タブレットを用いて自然な毛筆描画を質感良く再現できる。
【図面の簡単な説明】
【図１】本発明の毛筆描画装置の概観構成の一例を示した説明図である。
【図２】タブレット（タブレット板とタブレットペン）の構成例を示した説明図である。
【図３】座標入力面と表示装置とを一体的に構成した液晶ペンタブレットの外観構成を示した図である。
【図４】本発明の毛筆描画装置のハードウェア構成の一例を示した説明図である。
【図５】本実施の形態の毛筆描画装置のうち毛筆描画の軌跡を律する機能的構成の一例を示した説明図である。
【図６】描画パタンと筆圧（圧力値）の関係を示した説明図である。
【図７】描画パタンを作成するための各変数を定義する説明図である。
【図８】描画パタンの向きθとタブレットペンの移動方向の関係を示す。
【図９】カドにおける不自然な突起描画と、慣性を制御した場合の描画パタンの向きを示した描画概念図である。
【図１０】タブレットペンを急転回させたときに出現する不自然な突起描画の例を示した図である。
【図１１】本実施の形態の毛筆描画装置のうち描画パタン内の表現を変化させる機能的構成の一例を示した説明図である。
【図１２】毛筆描画装置で採用する描画パタンと描画パタン内部の濃淡画像（拡大図）の一例を示した図である。
【図１３】描画パタンに平滑化処理を順次施し、にじみが伝播する様子を示した図である。
【図１４】陰影パタンと描画例を示した図である。
【図１５】毛筆描画装置の描画例を示した図である。
【図１６】各種の描画モードによる毛筆描画例を示した図である。
【図１７】図１６に示した各種の描画モードのパラメータを表示した図表である。
【図１８】毛筆描画装置の処理流れについて説明したフローチャートである。
【図１９】コンピュータプログラムの処理結果を表示装置に表示させた場合の画面構成例を示した図である。
【図２０】コンピュータプログラムの処理結果を表示装置に表示させた場合の画面構成例を示した図である。
【図２１】コンピュータプログラムの処理結果を表示装置に表示させた場合の画面構成例を示した図である。
【図２２】コンピュータプログラムの処理結果を表示装置に表示させた場合の画面構成例を示した図である。
【図２３】コンピュータプログラムの処理結果を表示装置に表示させた場合の画面構成例を示した図である。
【図２４】コンピュータプログラムの処理結果を表示装置に表示させた場合の画面構成例を示した図である。
【図２５】画用紙の下地例を示した図である。
【図２６】キャンバス地の下地例を示した図である。
【図２７】描画パタンのサイズをカスタマイズする設定画面の一例を示した図である。
【図２８】濃淡画像などをカスタマイズする設定画面の一例を示した図である。
【図２９】インク（墨汁）をカスタマイズする設定画面の一例を示した図である。
【図３０】濃度とコントラストをカスタマイズする設定画面の一例を示した図である。
【図３１】染み込みの量と遅延制御をカスタマイズする設定画面の一例を示した図である。
【符号の説明】
１００ 毛筆描画装置
１０１ 本体装置
１０２ タブレット板
１０３ タブレットペン
１０４ 表示装置
１０５ キーボード
１０６ マウス
１２１ 座標入力面
１２２ ペンスタンド
１２３ 伝送線
１３１ ペン先部
１３２ 消しゴム部
１３３，１３４ サイドスイッチ
１５０ タブレット
４０１ ＣＰＵ
４０２ ＲＯＭ
４０３ ＲＡＭ
４０４ ハードディスク（ＨＤ）
４０５ グラフィックスカード
４４１ ＯＳ
４４２ 毛筆描画ソフト
４４３ ドライバソフト
５０１ 座標入力部
５０２ 座標値検出部
５０３ 圧力検知部
５０４ 描画パタン拡大縮小部
５０５ 移動方向算出部
５０６ 描画パタン回転部
５０７ 距離間隔算出部
５０８ 回転制御部
５０９ 転回判定部
５１０ 描画パタン短縮部
５１１ 描画部
５１２ 濃淡画像調整部
５１３ 停留判定部
５１４ 平滑化部
５１５ 停留回数計数部
５１６ 平滑化制御部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a brush writing device, a brush writing program, and a brush writing method, and in particular, a brush writing device including a tablet having a coordinate input surface and coordinate input means for inputting coordinates to the coordinate input surface, and a brush writing. The present invention relates to a program and a writing brush drawing method.
[0002]
[Prior art]
Conventionally, what realized various drawing functions using a computer was known. For example, it was possible to draw outlines such as lines and figures on a computer screen, and to fill, overwrite, and superimpose colors using each color. In addition, in order to make the operation feeling more intuitive, coordinate input may be performed using a so-called tablet. By using a tablet, it is possible to perform intuitive operations more than when using a mouse, and a drawing work similar to drawing with a real writing tool or drawing tool such as a paint brush or pastel can be realized on a computer.
[0003]
In particular, as a technique for realizing a drawing expression specialized for brush writing and brush writing, for example, Japanese Patent Application Laid-Open No. 6-222879 “Handwriting Display Method and Handwriting Display Device”, Japanese Patent Application Laid-Open No. 9-198823 Font creation software ", Japanese Patent Application Laid-Open No. 2000-330980," Handwritten style character output device and program recording medium thereof ", Japanese Patent Publication No. 6-79324," Method of generating calligraphy ", Japanese Patent No. 2912602," Method of drawing brush character " Etc. were known. Conventionally, an expression that approximates actual writing with a brush is realized by such a technique.
[Problems to be solved by the invention]
However, the conventional technique has the following problems.
That is, the conventional brush writing device using a tablet simply replaces the mouse with a tablet and pursues hardware-like imitation, and cannot reproduce actual brush writing with a good texture.
[0004]
Specifically, there is a problem that the reproducibility of the actual brush writing texture such as blurring and blurring is low. Also, with brushstroke drawing, sharp wrapping is developed at the “cadence” portion of the character, but there is a problem that unnecessary and unnatural protrusions are drawn simply by following the drawing pattern electronically. It was. In other words, the conventional brushstroke drawing has a problem that natural brushstroke drawing cannot be realized.
[0005]
The present invention has been made in view of the above, and an object of the present invention is to make it possible to reproduce natural writing with good texture using a tablet.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the brush writing apparatus according to claim 1 includes a tablet having a coordinate input surface and coordinate input means for inputting coordinates to the coordinate input surface, and has a basic shape for drawing. A brush writing apparatus that performs drawing according to a locus of a certain drawing pattern, and applies a smoothing filter to a plurality of black spot images in which the drawing pattern is randomly distributed in the drawing pattern, and the distance about the image is the center. A coordinate value detection unit configured to detect a coordinate value of a coordinate input by the coordinate input unit at a predetermined time interval, and a coordinate input unit are arranged on the coordinate input surface. In contrast, a pressure detecting means for detecting a pressure when inputting coordinates, and an enlargement for enlarging or reducing the size of the drawing pattern according to the pressure detected by the pressure detecting means. Reduction means, movement direction calculation means for calculating the movement direction of the coordinate input means based on the coordinate values sequentially detected by the coordinate value detection means, and a direction opposite to the movement direction calculated by the movement direction calculation means A drawing pattern rotating means for rotating the drawing pattern so that a writing tip portion of the drawing pattern faces, a distance interval calculating means for calculating a distance interval between adjacent coordinate values sequentially detected by the coordinate value detecting means, and the distance interval Based on the distance between coordinate values calculated by the calculation means, the drawing pattern rotation means is controlled, the rotation control means for reducing the rotation amount of the drawing pattern, and the pressure detected by the pressure detection means, and / or The number of the gray images and / or the size of the gray image according to the distance intervals of the coordinate values determined by the distance interval calculation means And / or a grayscale image adjusting means for adjusting the density of the grayscale image, rotated by the drawing pattern rotation means and the rotation control means, enlarged or reduced by the enlargement / reduction means, and adjusted by the grayscale image adjustment means And a drawing unit for sequentially drawing the drawing pattern at the coordinate position detected by the coordinate value detecting unit.
[0007]
That is, according to the first aspect of the present invention, the direction of the drawing pattern is gradually changed at the portion of the character to be drawn or the portion of the line in the diagram. In other words, the drawing pattern can be rotated with inertia. In addition, faint expression can be easily performed.
[0008]
Further, the brush writing apparatus according to claim 2 is a turn determination unit that determines whether or not the movement direction calculated by the movement direction calculation unit suddenly turns in the brush writing apparatus according to claim 1; When it is determined by the turning determination means that the moving direction has suddenly turned, pattern shortening means for shortening the length of the writing pattern brush tip by a predetermined drawing number or a predetermined drawing distance, and The drawing means is rotated by the drawing pattern rotation means and the rotation control means, enlarged or reduced by the enlargement / reduction means, adjusted by the grayscale image adjustment means, and shortened the length of the writing tip by the pattern shortening means. Drawing patterns are sequentially drawn at the coordinate positions detected by the coordinate value detecting means.
[0009]
That is, the invention according to claim 2 prevents unnecessary projection drawing due to the drawing pattern in steep folding drawing such as “splash”.
[0010]
The brush writing apparatus according to claim 3 includes a tablet having a coordinate input surface and coordinate input means for inputting coordinates to the coordinate input surface, and draws according to a locus of a drawing pattern which is a basic shape of drawing. And a coordinate value detecting means for detecting the coordinate value of the coordinates input by the coordinate input means at predetermined time intervals, and the coordinate input means sets the coordinates with respect to the coordinate input surface. The pressure detection means for detecting the pressure when inputting, the enlargement / reduction means for enlarging or reducing the size of the drawing pattern according to the pressure detected by the pressure detection means, and the coordinate value detection means are sequentially detected. A movement direction calculation means for calculating the movement direction of the coordinate input means based on the coordinate values obtained, and a drawing pattern in a direction opposite to the movement direction calculated by the movement direction calculation means. A drawing pattern rotating means for rotating the drawing pattern so that the writing tip portion faces, a distance interval calculating means for calculating adjacent distance intervals of coordinate values sequentially detected by the coordinate value detecting means, and a distance interval calculating means. The drawing pattern rotation means is controlled based on the calculated coordinate value distance interval, the rotation control means for reducing the rotation amount of the drawing pattern, and the coordinate input based on the coordinate value detected by the coordinate value detection means. A stop determining means for determining whether or not the means is stopped; and a smoothing means for performing a smoothing process on the drawing pattern when it is determined by the stop determining means that the coordinate input means is stopped. Rotated by the drawing pattern rotation means and the rotation control means, enlarged or reduced by the enlargement / reduction means, and smoothed by the smoothing means The image pattern, characterized in that and a drawing means for sequentially rendering the detected coordinate position by the coordinate value detection means.
[0011]
In other words, the invention according to claim 3 enables blurring expression.
[0012]
Further, the writing brush drawing apparatus according to claim 4 is the turning determination means for determining whether or not the moving direction calculated by the moving direction calculating means is suddenly turned in the writing brush drawing apparatus according to claim 3; A pattern shortening unit that shortens the length of the writing pattern by the predetermined drawing number or a predetermined drawing distance when the turning determination unit determines that the moving direction has suddenly turned; and
The drawing means is rotated by the drawing pattern rotation means and the rotation control means, enlarged or reduced by the enlargement / reduction means, smoothed by the smoothing means, and length of the writing tip by the pattern shortening means. The drawing pattern shortened is sequentially drawn at the coordinate position detected by the coordinate value detecting means.
[0013]
That is, the invention according to claim 4 prevents unnecessary projection drawing due to the drawing pattern in steep folded drawing such as “splash”.
[0014]
In addition, the writing brush drawing apparatus according to claim 5 is the stationary brush counting apparatus according to claim 3 or 4, wherein the stationary determination means counts the number of times the coordinate input means is stopped at the same place. And smoothing control means for controlling the smoothing means to increase the diffusion parameter of the smoothing process according to the number of times counted by the stationary number counting means, and the drawing means further comprises the smoothing The smoothed drawing pattern is drawn under the control of the image forming control means.
[0015]
That is, the invention according to claim 5 enables dynamic blurring expression.
[0016]
The writing brush drawing program according to claim 6 is a drawing which is a basic shape of drawing using an output signal from a tablet having a coordinate input surface and coordinate input means for inputting coordinates to the coordinate input surface. A program that draws a pattern according to its trajectory. The drawing pattern applies a smoothing filter to a plurality of black spot images randomly distributed in the drawing pattern, and the drawing color increases as the distance from the image increases. A coordinate value detecting means for detecting the coordinate value of the coordinate input by the coordinate input means at predetermined time intervals, and the coordinate input means with respect to the coordinate input surface. The pressure detection means for detecting the pressure when the coordinates are input and the size of the drawing pattern is enlarged according to the pressure detected by the pressure detection means An enlargement / reduction means for reducing, a movement direction calculation means for calculating a movement direction of the coordinate input means based on coordinate values sequentially detected by the coordinate value detection means, and a movement calculated by the movement direction calculation means. A drawing pattern rotating means for rotating the drawing pattern so that a writing tip portion of the drawing pattern faces in the opposite direction, and a distance interval calculating means for calculating a distance between adjacent coordinate values sequentially detected by the coordinate value detecting means. A rotation control means for controlling the drawing pattern rotation means based on the distance interval of the coordinate values calculated by the distance interval calculation means, and reducing the rotation amount of the drawing pattern; and the pressure detected by the pressure detection means. And / or according to the distance interval of the coordinate values determined by the distance interval calculation means, the number of grayscale images and / or the previous The grayscale image adjustment means for adjusting the size of the grayscale image and / or the density of the grayscale image, and rotated by the drawing pattern rotation means and the rotation control means, enlarged or reduced by the enlargement / reduction means, and the grayscale image adjustment The drawing pattern adjusted by the means is caused to function as a drawing means for sequentially drawing at the coordinate position detected by the coordinate value detecting means.
[0017]
That is, in the invention according to the sixth aspect, the drawing pattern gradually changes direction at the portion of the character to be drawn or the portion of the line in the diagram. In other words, the drawing pattern can be rotated with inertia. In addition, faint expression can be easily performed.
[0018]
According to a seventh aspect of the present invention, there is provided the writing brush drawing program according to the sixth aspect, wherein the computer further determines whether or not the moving direction calculated by the moving direction calculating means has suddenly turned. As a turn shortening means and a pattern shortening means for shortening the length of the brush tip of the drawing pattern by a predetermined drawing number or a predetermined drawing distance when the turning determination means determines that the moving direction has suddenly turned. The drawing means is rotated by the drawing pattern rotation means and the rotation control means, enlarged or reduced by the enlargement / reduction means, adjusted by the grayscale image adjustment means, and adjusted by the pattern shortening means. The drawing pattern shortened is sequentially drawn at the coordinate position detected by the coordinate value detecting means.
[0019]
That is, the invention according to claim 7 prevents unnecessary projection drawing due to the drawing pattern in steep folding drawing such as “splash”.
[0020]
The writing brush drawing program according to claim 8 is a drawing which is a basic shape of drawing using an output signal from a tablet having a coordinate input surface and coordinate input means for inputting coordinates to the coordinate input surface. A program for drawing a pattern in accordance with a trajectory, wherein the computer detects coordinate values of coordinates input by the coordinate input means at predetermined time intervals, and the coordinate input means inputs the coordinates. Pressure detecting means for detecting pressure when coordinates are input to the surface; scaling means for enlarging or reducing the size of the drawing pattern in accordance with the pressure detected by the pressure detecting means; and the coordinate values Based on the coordinate values sequentially detected by the detecting means, the moving direction calculating means for calculating the moving direction of the coordinate input means, and the moving direction calculating means A distance for calculating a distance between adjacent drawing values of the drawing pattern rotating means for rotating the drawing pattern so that the writing pattern is pointed in the direction opposite to the moving direction, and the coordinate values sequentially detected by the coordinate value detecting means An interval calculation unit, a rotation control unit that controls the drawing pattern rotation unit based on the distance interval of the coordinate values calculated by the distance interval calculation unit, and a rotation control unit that reduces the rotation amount of the drawing pattern; A determination unit for determining whether or not the coordinate input unit is stopped based on the detected coordinate value; and the drawing when the determination unit determines that the coordinate input unit is stopped by the stop determination unit. Smoothing means for performing a smoothing process on the pattern, rotated by the drawing pattern rotation means and the rotation control means, and enlarged or reduced by the enlargement / reduction means. The drawing pattern which is smoothed by the smoothing means, characterized in that to function as a drawing means for sequentially rendering the detected coordinate position by the coordinate value detection means.
[0021]
That is, the invention according to claim 8 enables blurring expression.
[0022]
In addition, in the writing brush drawing program according to claim 8, the writing brush drawing program according to claim 8 further determines whether or not the moving direction calculated by the moving direction calculation means has suddenly turned. As a turn shortening means and a pattern shortening means for shortening the length of the brush tip of the drawing pattern by a predetermined drawing number or a predetermined drawing distance when the turning determination means determines that the moving direction has suddenly turned. The drawing means is rotated by the drawing pattern rotation means and the rotation control means, enlarged or reduced by the enlargement / reduction means, smoothed by the smoothing means, and length of the writing tip by the pattern shortening means. The drawing pattern shortened is sequentially drawn at the coordinate position detected by the coordinate value detecting means.
[0023]
That is, the invention according to claim 9 prevents unnecessary protrusion drawing due to the drawing pattern in steep folding drawing such as “splash”.
[0024]
The writing brush drawing program according to claim 10 is the writing brush drawing program according to claim 8 or 9, wherein the computer further determines that the coordinate input means is stopped at the same place by the stop determination means. A stationary number counting unit that counts the number of times performed, and a smoothing control unit that controls the smoothing unit according to the number of times counted by the stationary number counting unit to increase a diffusion parameter of the smoothing process, and The drawing means is further characterized by functioning to draw a smoothed drawing pattern under the control of the smoothing control means.
[0025]
That is, the invention according to claim 10 enables dynamic blurring expression.
[0026]
The brushstroke drawing method according to claim 11 includes a tablet having a coordinate input surface and coordinate input means for inputting coordinates to the coordinate input surface, and draws according to a drawing pattern trajectory that is a basic shape of drawing. A brush writing method applied to a brush writing device for performing a coordinate value detection step of detecting coordinate values of coordinates input by the coordinate input means at predetermined time intervals, and the coordinate input in the coordinate input step A pressure detection step for detecting pressure when coordinates are input to the surface, an enlargement / reduction step for enlarging or reducing the size of the drawing pattern according to the pressure detected in the pressure detection step, and the coordinate values A moving direction calculating step of calculating a moving direction of the coordinate input means based on the coordinate values sequentially detected in the detecting step, and a direction opposite to the moving direction calculated in the moving direction calculating step; A drawing pattern rotation step of rotating the drawing pattern so that a writing tip portion of the drawing pattern faces, a distance interval calculating step of calculating a distance interval between adjacent coordinate values sequentially detected in the coordinate value detecting step, and the distance interval Based on the coordinate value detected in the coordinate value detection step, the rotation control step of controlling the rotation process in the drawing pattern rotation step based on the distance between the coordinate values in the calculation step to reduce the rotation amount of the drawing pattern A stop determination step for determining whether or not the coordinate input means is stopped, and a smoothing process that applies a smoothing process to the drawing pattern when it is determined in the stop determination step that the coordinate input means is stopped. Rotated through the drawing process, the drawing pattern rotation process and the rotation control process, enlarged or reduced through the enlargement / reduction process, and smoothed by the smoothing process. The drawing pattern, characterized in that it contains, and drawing step of sequentially drawn to the detected coordinate position in the coordinate value detecting step.
[0027]
That is, the invention according to claim 11 enables blurring expression.
[0028]
Further, the brush writing method according to claim 12 is the turning determination step of determining whether or not the moving direction calculated in the moving direction calculating step suddenly turns in the brush writing device according to claim 11; A pattern shortening step of shortening the length of the brush tip of the drawing pattern by a predetermined drawing number or a predetermined drawing distance when it is determined that the moving direction has suddenly turned in the turning determination step, The drawing step is rotated through the drawing pattern rotation step and the rotation control step, and is enlarged or reduced through the enlargement / reduction step, and the drawing pattern in which the length of the writing tip is reduced through the pattern shortening step, Drawing is sequentially performed at the coordinate position detected in the value detection step.
[0029]
That is, the invention according to claim 12 prevents unnecessary projection drawing due to the drawing pattern in steep folded drawing such as “splash”.
[0030]
The brush writing method according to claim 13 is the brush writing method according to claim 11 or 12, wherein the number of times the coordinate input means is determined to be stopped at the same place in the stop determination step is counted. And a smoothing control step of controlling a smoothing process in the smoothing step and increasing a diffusion parameter of the smoothing process according to the number of times counted in the stationary number counting step. In the drawing step, the drawing pattern smoothed under the control of the smoothing control step is further drawn.
[0031]
That is, the invention according to claim 13 enables dynamic blurring expression.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the present embodiment, the present invention is applied to a computer system, and its external configuration, hardware configuration, functional configuration, and processing flow will be described sequentially.
[0033]
(Brush writing device: external structure)
FIG. 1 is an explanatory view showing an example of an overview configuration of a brush writing apparatus according to the present invention. The writing brush drawing apparatus 100 includes a main body device 101 that performs calculations related to writing brush drawing processing, a tablet board 102 that includes a coordinate input surface that receives coordinate input, and a tablet pen (stylus pen) 103 that inputs coordinates to the coordinate input surface. And a display device 104 for displaying the drawing result, a keyboard 105, and a mouse 106. Hereinafter, the tablet plate 102 and the tablet pen 103 will be appropriately referred to as a tablet 150. Note that a configuration in which the keyboard 105 and the mouse 106 are excluded may be used depending on the mode of use.
[0034]
The main device 101 inputs information related to the coordinates output from the tablet 150 and executes each corresponding function. Specifically, it performs functions based on normal mouse actions such as clicking, double-clicking, right-clicking, dragging, scrolling, etc., based on the information related to coordinates, and various writing brush drawing modes (normal brush mode) , Solid brush mode, drought mode, thin brush mode, etc.) and erase the drawn image (eraser mode). The drawing mode or software processing will be described later. As the main body device 101, various computers including a personal computer can be used. Therefore, the main body device 101 can be said to be a computer device having an improved function as a writing brush drawing device. By using a personal computer or the like, the writing brush drawing apparatus 100 can be easily designed.
[0035]
The tablet board 102 detects input of coordinates by the tablet pen 103 and transmits the position information (absolute position information or relative position information) to the main body device 101 side as an auxiliary input device for realizing various functions. Play a role. The tablet pen 103 serves as an auxiliary input device for inputting coordinates to the tablet board 102 by touching or approaching a predetermined coordinate input area (coordinate input surface) on the tablet board 102.
[0036]
FIG. 2 is an explanatory diagram showing a configuration example of a tablet (tablet plate and tablet pen). The tablet board 102 has a one-to-one correspondence with the screen of the display device 104, a coordinate input surface 121 that accepts input of coordinates from the tablet pen 103, a pen stand 122 that stands up the tablet pen 103, a detection signal for presence / absence of coordinate input, And a transmission line 123 that transmits coordinate values and the like to the main apparatus 101. In addition to the detection signals and coordinate values described above, the tablet board 102 also generates pressure information, normal mouse signals such as right click, left click, double click, and drag by the tablet pen 103 and signals related to the eraser function described later. And a signal generator (not shown). Here, the mode in which the generation of coordinate values and pressure values and the coordinate input detection determination is performed on the tablet board 102 side has been described, but depending on the mode of use, it may be executed on the main body device 101 side.
[0037]
The tablet pen 103 provides a pen tip portion 131 having a pen pressure sensor to reproduce the actual drawing texture of a brushstroke when inputting coordinates to the coordinate input surface 121, and an eraser function (eraser mode) described later. It has an eraser unit 132 to be used, a side switch 133 for generating a right click signal for a mouse, and a side switch 134 for generating a double click signal. Needless to say, the side switches may be assigned in various ways, and the side switch 133 may be set to the left click and the side switch 134 may be set to the right click. In the present embodiment, the tablet 150 performs reading by an electromagnetic induction method (electromagnetic transfer action method), the writing pressure is 512 steps, the reading speed is 200 times per second, and the readable height is 5 mm. is doing. Therefore, it can be said that the coordinate input surface 121 is formed from 5 mm above the physical real surface.
[0038]
Further, as shown in the figure, the side switch 133 and the side switch 134 are integrally formed as a seesaw switch, but the present invention is not limited to this and may be a separate switch or button. A signal from the tablet pen 103 is detected on the tablet board 102 side, and transmitted from the signal generation unit to the main unit 101. In addition, although the writing pressure sensor is provided on the tablet pen 103 side here, the writing pressure sensor may be configured to detect the writing pressure on the coordinate input surface 121 side.
[0039]
In addition to the pen pressure function and the eraser function described below, the tablet pen 103 has a tilt detection function for detecting the tilt of the tablet pen 103 with respect to the coordinate input surface 121, and a plurality of tablet pens 103 can input a single coordinate. A device ID function for individually recognizing each tablet pen when operating on the surface 121 and a rotation detection function for detecting rotation with respect to the pen axis may be provided. The device ID function is assigned to each tool of the application software, and is used when multiple brushes (for example, thick brush, medium brush, and teacher red brush) are used properly without setting the menu each time. May be.
[0040]
The display device 104 displays various processing results (drawing results) executed by the main device 101. As the display device 104, a liquid crystal monitor or a CRT monitor can be used. In addition, a projector may be employed when performing at a large conference hall.
[0041]
The keyboard 105 is used when performing text input or command instruction as necessary. The mouse 106 is used to give various instructions through normal computer operations other than drawing.
[0042]
In this embodiment, a mode in which coordinate input is performed using the tablet board 102 and the tablet pen 103 will be described, but various coordinate input devices (coordinate input systems) can be employed as the tablet. That is, in the present invention, the coordinate input detection method is not particularly limited, and an electric type or magnetic type that detects an input by an electrical or magnetic change, or an optical that detects the intensity or weakness of light. A formula etc. can be adopted.
[0043]
Further, the coordinate input surface 121 and the display device 104 may be integrally configured, and may be configured as a so-called touch panel or a liquid crystal pen tablet. FIG. 3 is a diagram illustrating an external configuration of a liquid crystal pen tablet in which a coordinate input surface and a display device are integrally configured. As shown in the figure, since the coordinate input surface 121 and the display device 104 are integrated, the operator can use the tablet pen 103 to draw a very intuitive writing brush as if the display surface is a half paper. It becomes possible.
[0044]
(Brush writing device: hardware configuration)
Next, the hardware configuration of the brush writing apparatus 100 will be described. FIG. 4 is an explanatory diagram showing an example of a hardware configuration of the brush writing apparatus according to the present invention. The brush writing apparatus 100 has a CPU 401, a ROM 402, a RAM 403, a hard disk (HD) 404, a graphics card 405, a tablet board 102, a tablet pen 103, a display device 104, a keyboard (as a hardware configuration). K / B) 105 and a mouse (MOUSE) 106.
[0045]
The CPU 401 controls the entire writing brush drawing apparatus 100 together with the OS, and controls various software processes. Specifically, for example, the CPU 401 executes various functions set at the position of the coordinates based on the coordinate information and pressure information from the tablet 150 in accordance with a program stored in the hard disk 404 or the ROM 402. The CPU 401 also performs drawing control for the VRAM (image RAM) of the graphics card 405 or control for temporarily storing work data stored in the hard disk 404 in the RAM 403.
[0046]
The ROM 402 stores a boot program and the like. Depending on the mode of use, the ROM 402 may store a control program for the tablet 150. The RAM 403 is used as a work area for the CPU 401. Specifically, various programs read from the hard disk 404 are temporarily stored. In addition, the RAM 403 temporarily stores coordinate information and pressure information received from the tablet board 102 and the mouse 106. This information is used as auxiliary information when executing a function corresponding to the corresponding application or icon. In particular, in the present invention, it is also used as information for controlling the drawing pattern.
[0047]
The hard disk 404 stores various software programs (software) such as an operating system (OS), application programs, and drivers.
[0048]
The graphics card 405 transmits an image signal to be output to the display device 104. The graphics card 405 also includes a VRAM that stores an image signal to be output, and an image output interface (image output I / F) that outputs the processed image signal to the display device 104. As an operation, the image output I / F outputs RGB image data expanded in the VRAM to the display device 104.
[0049]
Although not shown, the brush drawing apparatus 100 also includes an input interface (input I / F) that performs input control of coordinate information input to the coordinate input surface 121. For the input I / F, a connection mode such as RS232C or USB can be adopted. Based on the coordinate information input from the coordinate input I / F, various processes including a drawing process are executed via the CPU 401 and the OS of the hard disk 404 and the corresponding application.
[0050]
In addition, the brush writing apparatus 100 can be mounted with a flexible disk drive device, a CD-ROM drive device, an MO drive device, and the like.
[0051]
The hard disk 404 stores an OS 441, brush writing software 442 that realizes brush writing, and driver software 443 that controls the tablet 150 so that it can be used by the brush writing device 100. In addition, the hard disk 404 stores various software such as word processing software and spreadsheet software.
[0052]
The driver software 443 emulates a signal generated by the tablet 150 into a mouse event and controls it so that it can be interpreted by the OS 441. In addition, each point on the coordinate input surface 121 is in one-to-one correspondence with the coordinate space managed by the OS. Perform the corresponding control. The coordinate position may be calculated by grasping the coordinate value on the tablet 150 side and sending it to the main device 101 side, or receiving a predetermined signal from the tablet 150 side on the main device 101 side. A configuration in which the coordinate value is grasped on the apparatus 101 side may be employed. Similarly, the pressure (writing pressure) when the tablet pen 103 is inputting coordinates to the tablet plate 102 may be a mode in which the pressure value is grasped on the tablet 150 side and sent to the main body device 101 side. Alternatively, a configuration may be adopted in which a predetermined signal from the tablet 150 side is received on the main device 101 side and is grasped as a pressure value on the main device 101 side.
[0053]
(Functional configuration of the brush writing apparatus 100: functional configuration related to the locus of the drawing pattern)
Next, among the functional configurations of the writing brush drawing apparatus 100, a functional configuration relating to drawing control of the drawing pattern locus will be described. The writing brush drawing apparatus 100 performs drawing in various writing brush drawing modes according to the writing brush drawing software 442 in conjunction with the tablet 150. The brush writing mode is roughly divided into a drawing execution mode that reproduces high quality brush drawing that takes into account the type of brush and the amount of ink, and an erasing mode that erases the locus drawn in the drawing execution mode (eraser mode). , Can be divided into
[0054]
The drawing execution mode is a normal brush mode that reproduces the normal brush brush drawing texture, a solid brush mode that reproduces the brush brush drawing texture that does not cause blurring almost enough, a red ink brush mode that reproduces blurring expression, and a ink brush that is sufficiently saturated It is composed of a thin ink brush mode in which The brush writing apparatus 100 mainly reproduces brush writing using ink juice with a good texture, but also has a brush brush watercolor mode and a brush oil painting mode in consideration of the advantages realized by a computer system. Further, although the background is assumed to have no particular unevenness, such as a half paper, in addition to this, background processing for realizing writing brush writing on the uneven background is also executed. These will be described later.
[0055]
FIG. 5 is an explanatory diagram showing an example of a functional configuration that regulates the trajectory of writing brush in the writing brush drawing apparatus of the present embodiment. The writing brush drawing apparatus 100 includes a coordinate input unit 501, a coordinate value detection unit 502, a pressure detection unit 503, a drawing pattern enlargement / reduction unit 504, and a movement direction calculation unit 505 as functional configurations that regulate the trajectory of writing brush drawing. A drawing pattern rotation unit 506, a distance interval calculation unit 507, a rotation control unit 508, a turn determination unit 509, a drawing pattern shortening unit 510, and a drawing unit 511.
[0056]
The coordinate input unit 501 inputs coordinate information. The coordinate information is information input to the tablet board 102 and includes the coordinate value itself or information necessary for calculating the coordinate value. Different erasing modes, continuous input time, etc. can also be included. The coordinate input unit 501 can realize its function by, for example, the tablet 150, the driver software 443, and the like.
[0057]
The coordinate value detection unit 502 detects the coordinate value of the coordinate input by the coordinate input unit 501 at predetermined time intervals. The coordinate value may be an absolute coordinate or a relative coordinate. Further, the coordinate system may be based on the resolution (800 × 600 pixels, 1024 × 768 pixels, etc.) set by the OS 441, or the actual measurement value (coordinate input surface 121 is configured as a 127 mm × 99 mm surface, and the reading resolution is set. (Mm measurement value set to ± 0.25 mm)). The coordinate value detection unit 502 can realize its function by, for example, the tablet 150, the RAM 402, the OS 441, the driver software 443, and the like.
[0058]
The pressure detection unit 503 detects a pressure value when the tablet pen 103 is inputting coordinates to the coordinate input surface 121. In the following, this pressure will be referred to as writing pressure as appropriate. The drawing pattern enlargement / reduction unit 504 enlarges or reduces the size of the drawing pattern to be drawn by the drawing unit 511 according to the pressure detected by the pressure detection unit 503. Specifically, when the pressure is high or high, the drawing pattern is increased, and when the pressure is low or low, the drawing pattern is reduced. Here, “enlargement or reduction” does not mean only a similar shape, but also includes changes in the width of the brush root portion and the brush tip portion of the drawing pattern and the length of the brush tip portion from the brush root portion. Next, specific enlargement / reduction processing will be described.
[0059]
FIG. 6 is an explanatory diagram showing the relationship between the drawing pattern and the writing pressure. Among these, FIG. 6A and FIG. 6C show a drawing pattern of a round brush generally used in calligraphy, and FIG. 6B shows a drawing pattern of a flat brush. It is a figure. As shown in the drawing, in the case of a round brush, a drawing pattern is expressed by two figures based on a circular shape at the base portion and a trapezoidal shape at the tip portion. On the other hand, in the case of a flat brush, a drawing pattern is expressed by a figure of only a trapezoid.
[0060]
As the shape change (enlargement / reduction processing) of the drawing pattern by the writing pressure, there is a method of performing control to maximize the root width when the writing pressure value is maximum and to make the width of the writing tip wider than the root width. At this time, it is preferable to perform control to shorten the brush length and narrow the brush width as the pen pressure value decreases. More specifically, in the case of a round brush, in the state where the pen pressure is minimum, the width of the tip is made smaller than the width of the base, and control is performed so that the shape is close to a combination of two shapes, the base is circular and the tip is triangular. Do it. In the case of a flat brush, control is performed so that the length of the brush is close to a rectangular shape shorter than the width of the brush when the pressure is minimum.
[0061]
As an example of realizing the shape change shown in FIG. 6 and described above, the following shape determination formula can be adopted. FIG. 7 is an explanatory diagram for defining each variable for creating a drawing pattern.

It should be noted that the initial brush size (large brush, medium brush) can be freely set using the brush length (L1), root width (W2), and brush tip width (W1) at the time of maximum pressure used in this calculation formula as variable parameters. , Small brush) may be changed.
[0062]
In the above equation, a drawing model in which the writing tip spreads as the writing pressure increases is used. However, a drawing model in which the writing tip shape does not depend on the writing pressure may be employed (see FIG. 6C). In this case, it is preferable to use a drawing pattern with a closed brush tip so that the beginning of writing and drawing of fine characters are not thick and unnatural.
[0063]
The function of the pressure detection unit 503 can be realized by, for example, the tablet 150 and driver software 443. The drawing pattern enlargement / reduction unit 504 can realize its function by, for example, the CPU 401, the RAM 403, and the writing brush software 442.
[0064]
The movement direction calculation unit 505 calculates the movement direction of the tablet pen 103 based on the coordinate values sequentially detected by the coordinate value detection unit 502. The drawing pattern rotation unit 506 rotates the drawing pattern so that the writing tip portion of the drawing pattern faces in the direction opposite to the movement direction calculated by the movement direction calculation unit 505. The brush writing apparatus 100 draws a drawing pattern corresponding to the sampling points (sequentially detected coordinate values) of the tablet board 102 and performs brush writing by interpolating between the sampling points. The drawing pattern rotating unit Reference numeral 506 denotes processing for changing the direction of the brush tip in accordance with the direction of travel of the brush at each sampling point.
[0065]
As processing at this time, first, it is necessary to determine the initial brush tip angle when the tablet pen 103 is lowered. The writing brush drawing apparatus 100 skips sampling points until the tablet pen 103 starts to input coordinates (position where it touches the tablet board 102) until it moves a certain distance or more, and the point where the distance exceeds a certain distance. A method is used in which the traveling direction of the tablet pen 103 is obtained from the coordinate value and the coordinate value at the start of input, and the orientation (initial angle) of the drawing pattern is calculated in accordance with this direction.
[0066]
This is because camera shake is likely to occur before and after the writing of the brush. For example, from the sampling point immediately before the tablet pen 103 is lowered and the sampling point when the tablet pen 103 touches the tablet plate 102 (coordinate input is started). This is because when the brush traveling direction is obtained and the initial angle is calculated, the movement amount of the brush is small and the calculation error becomes very large. Note that the threshold value of the movement distance of the tablet pen 103 for determining the initial angle can be set to a quarter of the maximum length L1 of the drawing pattern (see FIG. 7).
[0067]
After the initial angle is determined, the movement direction calculation unit 505 and the drawing pattern rotation unit 506 sequentially obtain the direction of the straight line connecting the sampling points, and rotate the writing pattern writing tip. The position of the previous tablet pen 103 is (x_i-1, Y_i-1), The current position (x_i, Y_i), The drawing pattern orientation θ is
θ = Tan^-1(-(Y_i-Y_i-1) / (X_i-X_i-1)) ... Formula (1)
It becomes. FIG. 8 shows the relationship between the drawing pattern direction θ and the movement direction of the tablet pen.
[0068]
The movement direction calculation unit 505 can realize its function by, for example, driver software 443, RAM 403, CPU 401, brush writing software 442, and the like. The drawing pattern rotation unit 506 can realize its function by, for example, the RAM 403, the CPU 401, and the brushstroke drawing software 442.
[0069]
The distance interval calculation unit 507 calculates the adjacent distance interval between the coordinate values sequentially detected by the coordinate value detection unit 502. Further, the rotation control unit 508 controls the drawing pattern rotation unit 506 based on the distance interval of the coordinate values calculated by the distance interval calculation unit 507 to reduce the rotation amount of the drawing pattern. In other words, the rotation control unit 508 realizes drawing in consideration of “inertia” in the quadrant. In other words, unnatural projections at the edges are prevented.
[0070]
When the actual writing with a brush is observed in detail, the direction of the brush does not change rapidly due to factors such as friction, but changes gradually with a little delay. In order to express such characteristics, the brush writing apparatus 100 is provided with a parameter called “inertia” so that the degree of change in brush direction (drawing pattern rotation) can be freely adjusted. Note that, except for the initial angle when the tablet pen 103 is lowered, the amount of change in the direction of the brush is adjusted by this inertia parameter.
[0071]
When drawing with inertia using the brush writing apparatus 100, the rotation control unit 508 uses the rotation angle θ ′._iIs calculated by the following equation.
θ ′_i  = Θ ’_i-1+ (100-m) · Δθ_i  / 100 ... Formula (2)
Δθ_i  = Θ_i−θ ′_i-1  (−π <Δθ_i≦ π)
here,
θ ′_i-1    Rotation angle at sampling point i-1 (with inertia)
θ_i        The direction opposite to the movement direction of the tablet pen 103 at the sampling point i obtained by the movement direction calculation unit 505 (no inertia)
Δθ_i      Change amount of rotation angle at sampling point i-1 (-π to π)
m Inertia (0-100)
Θ ’_i-1The initial angle described above is used immediately after paper is received (immediately after the start of coordinate input), and the rotation angle calculated by the equation (2) is used at the immediately preceding sampling point otherwise. Δθ_iUses an angle normalized to a range of −π to π.
[0072]
As is clear from equation (2), the greater the value of inertia m, the slower the rotation. When m = 100, it does not rotate at all (θ ′_i  = Θ ’_i-1), When m = 100, the opposite direction θ ′ of the moving direction of the tablet pen 103_i= Θ_iIt becomes.
[0073]
The above is the process of determining the orientation of the drawing pattern using the inertia m. In the brush writing apparatus 100, the inertia m is changed according to the moving speed of the tablet pen 103. As a result, when the drawing pattern is simply overlapped and drawn at the position detected by the coordinate value detection unit 502, an unnatural protrusion generated at the folded portion of the character can be prevented. FIG. 9 is a drawing conceptual diagram showing unnatural protrusion drawing in the CAD and the drawing pattern direction when the inertia is controlled. Among these, FIG. 9A is a drawing that does not take inertia into consideration, and FIG. 9B is a drawing that shows the orientation of the drawing pattern before and after the quadrature portion of the drawing shown in FIG. 9A. FIG. 9C is a diagram showing the orientation of the drawing pattern in consideration of inertia.
[0074]
The unnatural protrusion is caused by the fact that the drawing pattern is rotated before the pen is fully lowered when the pen is moved slowly. The rotation control unit 508 performs rotation control so that the inertia m is increased when the moving speed of the tablet pen 103 is low. For example, the following expression can be used for the rotation control.
m ’_i  = MAX (100-rf_i, M)
rf_i  = (D_i ²・ Α) / (MAX (l1_i, L1_i-1) + 1) + β
(However, D_iRf if = 0_i= 0)
D_i ²  = (X_i-X_i-1)²  + (Y_i-Y_i-1)²
here,
m ’_i      Corrected inertia value at sampling point i (0 to 100)
m Inertia value before correction (0 to 100) (used as lower limit)
rf_i        Rotation coefficient at sampling point i
D_i        Distance between sampling point i and sampling point i-1
l1_i        Length of drawing pattern at sampling point i
l1_i-1      Length of drawing pattern at sampling point i-1
α, β Constants for fine adjustment (eg α = 10, β = 3)
x_i, Y_i      Coordinate value of sampling point i
x_i-1, Y_i-1    Coordinate value of sampling point i-1
Coordinates are managed as integer values.
Therefore, the final rotation angle θ ′_iIs as follows.
θ ′_i  = Θ ’_i-1+ (100-m '_i) ・ Δθ_i  / 100 ... Formula (3)
[0075]
As described above, drawing is performed while changing the inertia value m in accordance with the moving speed of the tablet pen 103, thereby suppressing unnatural projections at the edges. Further, not only in the CAD portion, but when the pen is moved slowly, an unnatural bulge may occur in the middle of the line due to an increase in camera shake and calculation error, but this phenomenon is also eliminated at the same time. The distance interval calculation unit 507 can realize its function by, for example, the brush drawing software 442, the RAM 403, the CPU 401, and the like. The rotation control unit 508 can realize its function by, for example, the brush drawing software 442, the RAM 403, the CPU 401, and the like.
[0076]
The turning determination unit 509 determines whether or not the moving direction calculated by the moving direction calculation unit 505 has suddenly turned. Further, the drawing pattern shortening unit 510 shortens the length of the drawing pattern by a predetermined drawing number or a predetermined drawing distance when the turning determination unit 509 determines that the moving direction has suddenly turned. When a significant change of direction close to 180 degrees such as folding is performed, an unnatural protrusion may be drawn even if inertia is taken into consideration (see FIG. 10), and the drawing pattern shortening unit 510 uses this protrusion. Prevent drawing.
[0077]
When the actual writing brush drawing is observed in detail, in practice, a beautiful drawing is realized by turning over the brush tip at the folded portion. The brush writing apparatus 100 addresses this problem by simulating the tip turning over. Specifically, first, in order to determine whether the brush tip is turned over, the tip rotation rate rr at each sampling point._iCalculate
rr_i  = | Δθ_i| · 100 / π (4)
Δθ_i  = Θ_i−θ ′_i-1  (−π <Δθ_i≦ π)
here,
rr_i      Tip rotation rate at sampling point i
θ ′_i-1    Rotation angle (with inertia) at sampling point i-1 obtained by equation (3)
θ_i      Rotation angle at sampling point i obtained by equation (1) (no inertia)
Δθ_i    Change amount of rotation angle at sampling point i-1 (-π to π)
[0078]
The turning determination unit 509 calculates the tip rotation rate rr calculated by the equation (4)._iIt is determined that the tip of the brush is turned over, that is, the moving direction has suddenly turned. This constant value may be 80, for example. When it is determined that the brush tip is turned over, the writing brush drawing apparatus 100 sets the brush tip reversal flag, stores the coordinate value (tx, ty) at the sampling point, and sets the rotation angle to θ ′._i-1= Θ_i, Θ ’_i= Θ_iAs a drawing.
[0079]
The drawing pattern shortening unit 510 employs a drawing pattern in which the length of the writing tip is temporarily shortened when the writing tip reversal flag is set. Brush length l1_iFor example, 'can be calculated by the following formula.
l1_i′ = Dt_i・ (L1_i-W2_i) / L1 + w2_i      (For round brush)
l1_i′ = Dt_i・ L1_i  / L1 (for flat brush)
Dt_i  = Sqrt ((x_i-T_x)²+ (Y_i-T_y)²)
However, Dt_iDt for> L1_i= L1
here,
Dt_i        The distance from the turning point of sampling point i
x_i, Y_i      Coordinate value of sampling point i
tx, ty Coordinate value of turning point
w2_i        Width of drawing pattern root at sampling point i
l1_i          Length of drawing pattern at sampling point i
Maximum length of L1 drawing pattern
Note that the distance Dt from the turning point of the sampling point i_iMay be approximated by the following equation:
Dt_i  = | X_i−tx | + | y_i−ty | However, Dt_iDt for> L1_i= L1
[0080]
The turn determination unit 509 performs Dt_iWhen ≧ L1, the process of clearing the brush tip reversal flag is performed. In this way, when it is determined that the tip of the brush is turned over, the tip of the tip is simulated by temporarily correcting the length of the brush tip and drawing with a drawing pattern that is close to a circle. When it is performed, that is, the drawing defect at the turn-back point can be solved.
[0081]
The turn determination unit 509 can realize its function by, for example, the brush drawing software 442, the RAM 403, the CPU 401, and the like. When the tablet pen 103 has an inclination detection function for detecting an inclination with respect to the coordinate input surface 121, the tablet pen 103 is also a functional component of the turn determination unit 509. The drawing pattern shortening unit 510 can realize its function by, for example, the brush writing software 442, the RAM 403, the CPU 401, and the like.
[0082]
The drawing unit 511 detects coordinate values of the drawing pattern rotated by the drawing pattern rotation unit 506 or the rotation control unit 508, enlarged or reduced by the drawing pattern enlargement / reduction unit 504, and shortened by the drawing pattern shortening unit 510. Drawing is sequentially performed at the coordinate positions detected by the unit 502. In drawing, a drawing pattern for interpolation is drawn between the sampling points to perform a process of filling the gaps between them. At this time, if drawing is performed simply using a similar drawing pattern, the interpolation pattern should be drawn so that the hot spot of the drawing pattern overlaps the position of the point that forms a straight line connecting the sampling points. That's fine. However, the drawing model employed in the brush writing apparatus 100 changes the shape of the drawing pattern depending on the writing pressure and the direction of travel of the writing brush, so the tip of the writing brush may draw a longer track than the straight line connecting the sampling points. In the interpolation process, there are gaps in some places, and smooth interpolation cannot be performed.
[0083]
Therefore, the drawing unit calculates the number of interpolation points based on the length of the longest straight line among the straight lines connecting the vertices of the polygon that forms the drawing pattern at each sampling point, and the pen pressure and the traveling direction at each interpolation point. It also performs the process of drawing the drawing pattern that is created by gradually changing.
[0084]
In the case of a round brush, find the straight line distance between the points on the circumference showing the root part of the brush and the vertices of the trapezoid indicating the tip of the brush, and in the case of a flat brush, each vertex of the trapezoid showing the tip of the brush Find the straight-line distance between each other. The number of interpolation points is determined from the length of the longest distance between the vertices. Specifically, assuming that the starting end coordinates of the reference straight line are (x1, y1) and the end coordinates are (x2, y2), if | x2-x1 | ≧ | y2-y1 |, the number of interpolation points is | x2-x1 | When | x2-x1 | <| y2-y1 |, the number of interpolation points is | y2-y1 |. The coordinate value is an integer value.
[0085]
The drawing unit 511 calculates the coordinates of each interpolation point based on the number of interpolation points obtained in this way, and draws so that the hot spot of the drawing pattern at each interpolation point follows a straight line connecting each sampling point. . In addition, since the trace of the line connecting the vertices of the drawing pattern draws a curve in actual drawing, the number of interpolation points obtained by multiplying the number of interpolation points by 1.2 to 1.5 may be used. The amount of change in variables such as writing pressure and rotation angle during interpolation is obtained by dividing the difference of each variable between two points to be interpolated by the number of interpolations.
[0086]
The brush writing apparatus 100 enables high-quality brush writing by the drawing processing of the drawing unit 511. The drawing unit 511 can realize its function by, for example, the brush writing software 442, the RAM 403, the CPU 401, the graphics card 405, the display device 104, and the like.
[0087]
(Functional configuration of writing brush drawing apparatus 100: functional configuration relating to expression of drawing pattern itself)
Next, among the functional configurations of the brush drawing apparatus 100, a functional configuration relating to the expression of the drawing pattern itself will be described. In an actual writing brush drawing, a plurality of factors such as the bundle of hairs constituting the writing brush, the amount of ink, the ease of bleeding of ink, and the ease of separation are intertwined to form a drawing texture peculiar to the writing brush (fading or blurring). In the writing brush drawing apparatus 100, the drawing texture is expressed by changing the internal image of the drawing pattern.
[0088]
FIG. 11 is an explanatory diagram showing an example of a functional configuration for changing the internal image of the drawing pattern in the brush writing apparatus according to the present embodiment. The writing brush drawing apparatus 100 has a grayscale image adjustment unit 512, a stop determination unit 513, a smoothing unit 514, a stop count counting unit 515, and a smoothing control unit 516 as functional configurations that change the expression in the drawing pattern. And having. Here, first, a general gray image inside the drawing pattern will be described, and then each functional configuration will be described.
[0089]
FIG. 12 is a diagram illustrating an example of a drawing pattern employed in the writing brush drawing apparatus 100 and a grayscale image inside the drawing pattern. By using a drawing pattern with shading or gaps, it is possible to draw with a high texture reflecting the trajectory of each brushstroke. As a drawing pattern generation method, for example, there is a method in which a point pattern that gradually decreases as it moves away from the center is randomly placed in the drawing pattern. Specifically, the following point patterns can be used.
P_xy= A ・ D_xy ²                      (0 ≦ P_xy≦ 255)
(However, P_xyP for> 255_xy  = 255)
here,
P_xy          Pixel brightness (color value)
D_xy          The distance between the center point and its pixel
a Coefficient for adjusting spread
In the drawing pattern, the amount of the gap can be adjusted by adjusting the value of the coefficient a of the point pattern.
[0090]
In addition to this method, for example, a random number of random points is generated using random numbers, and this point is blurred by a smoothing filter according to the drawing mode, so that the brightness level is set so that the drawing pattern does not become thin. You may obtain by correcting.
[0091]
The smoothing filter is a processing filter that pays attention to a certain central pixel (target pixel) and neighboring pixels and averages the colors in the specified adjacent range. Note that when a rectangular filter is used, a square blur is used. Therefore, a round blur may be applied with different weights depending on the distance from the target pixel.
[0092]
In the following, a unit image that has been subjected to a point pattern or a smoothing filter and is blurred or blurred will be referred to as a grayscale image. By adjusting the grayscale image, it is possible to reproduce the faintness and blurring peculiar to writing brushes with a good texture.
[0093]
First, a functional unit that can express blur will be described. The grayscale image adjustment unit 512 adjusts the number, size, and grayscale of the grayscale images according to the pressure detected by the pressure detection unit 503 and the distance interval between the coordinate values determined by the distance interval calculation unit 507. In addition, depending on the mode of use, it may be a mode that depends only on the pressure, or a mode that depends only on the distance interval. Moreover, the aspect which adjusts only a number may be sufficient, the aspect which adjusts only a magnitude | size may be sufficient, and the aspect which only adjusts light and shade may be sufficient. Moreover, the aspect which adjusts two among a number, a magnitude | size, and lightness and darkness may be sufficient.
[0094]
In the writing brush drawing apparatus 100, in order to reduce the calculation processing load, for example, the size of the point is limited to three levels, large, medium, and small, and the parameter adjustment at the time of luminance level correction is used in combination, so that the gaps are apparently continuous. The amount can be adjusted. The adjustment of the grayscale image is determined at an initial stage when the drawing mode is selected, and is dynamically changed during the drawing. The adjustment by the grayscale image adjustment unit 512 can automatically increase or decrease the gap amount depending on the writing pressure or the speed of the tablet pen 103. As a result, it is possible to achieve a faint expression with high texture. The grayscale image adjustment unit 512 can realize its function by, for example, the writing brush drawing software 442, the RAM 403, the CPU 401, and the like.
[0095]
Next, a functional unit that expresses blur will be described. The stationary determination unit 513 determines whether or not the tablet pen 103 is stationary based on the coordinate values detected by the coordinate value detection unit 502. The smoothing unit 514 performs a smoothing process on the drawing pattern when the stop determination unit 513 determines that the tablet pen 103 is stopped. The stationary number counting unit 515 counts the number of times that the stationary determination unit 513 determines that the tablet pen 103 is stationary at the same place. The smoothing control unit 516 controls the smoothing unit 514 according to the number of times counted by the stationary number counting unit 515 to increase the diffusion parameter of the smoothing process.
[0096]
In actual writing brush drawing, when ink ink (for example, light ink) that can easily separate ink and water is sufficiently soaked in the brush, bleeding is observed particularly at the stopping point. In the writing brush drawing apparatus 100, when the tablet pen 103 is stopped, a smoothing filter having a large diffusion coefficient is applied to the drawing pattern according to the stopping time, and the drawing pattern is drawn. A smoothing process is adopted for reproduction of the blur. At this time, it is possible to simply express how the density gradually decreases by not performing luminance correction. FIG. 13 is a diagram illustrating a state in which blurring is propagated by sequentially performing a smoothing process on the drawing pattern. Note that, instead of gradually increasing the diffusion coefficient, the previously used drawing pattern is stored, and the blurring propagation can be expressed by using the drawing pattern that has been subjected to the smoothing process over the drawing pattern.
[0097]
The functions of the smoothing unit 514 and the smoothing control unit 516 can be realized by, for example, the brush writing software 442, the RAM 403, the CPU 401, and the like. The number-of-stops counting unit 515 can realize its function by, for example, the tablet board 102, the driver software 443, the brush writing software 442, and the like.
[0098]
The drawing unit 511 sequentially draws the drawing patterns determined or adjusted through the processing of these functional units that change the grayscale image in the drawing pattern at the coordinate positions input by the tablet pen 103. Note that the brush writing device 100 reproduces a brush brush drawing using ink juice on the display device 104 with a high texture, but in addition to this, drawing with a watercolor brush or an oil brush can be reproduced using a similar algorithm. In particular, when reproducing an oil brush, an emboss filter may be applied to the drawing pattern to add a shadow. FIG. 14 is a diagram showing a shadow pattern and a drawing example. Among these, FIG. 14A shows a drawing pattern before processing, FIG. 14B shows a drawing pattern after applying an emboss filter, and FIG. 14C shows a drawing example. .
[0099]
(Drawing sample of writing brush drawing device 100)
Next, a drawing example of the writing brush drawing apparatus 100 is shown. FIG. 15 is a diagram illustrating a drawing example of the writing brush drawing apparatus. As shown in the drawing, it can be seen that drawing expression equivalent to the actual brushstroke drawing, such as “Tome”, “Hane”, “Harai”, and “Kaesashi”, is possible. In particular, it can be confirmed that the textures of where the tablet pen 103 starts to input coordinates and where the input of coordinates has ended are reproduced very well.
[0100]
FIG. 16 is a diagram illustrating examples of brushstroke drawing in various drawing modes. FIG. 17 is a chart displaying parameters of various drawing modes shown in FIG. As shown in the figure, a round brush represents a drawing mode of a normal brush, a solid brush, a red brush, and a thin brush, and a flat brush represents a drawing mode of a watercolor brush or an oil brush. It can be seen that various drawing expressions are possible by appropriately setting the parameters.
[0101]
The brush writing apparatus 100 also has an eraser mode. The eraser mode is a mode in which, when the eraser unit 132 of the tablet pen 103 is inputting coordinates on the coordinate input surface 121, the line drawing of the traced portion is erased along the locus. With the eraser mode, it is possible to realize a drawing texture that is different from the undo function of a computer system. Since the eraser mode is linked to the tablet pen 103, the troublesomeness of the eraser mode selection that has been realized by multiple icon clicks or pull-down selections as in the past is eliminated, and the brush writing apparatus 100 is used. It becomes possible to improve the operability.
[0102]
(Processing flow of brush writing device)
Next, a processing flow of the brush writing apparatus 100 will be described. FIG. 18 is a flowchart illustrating an example of a processing flow of the brush drawing apparatus 100. The brush writing apparatus 100 first determines a drawing mode (step S601). Specifically, a drawing pattern and a control parameter during drawing of the drawing pattern are determined (see FIG. 17).
[0103]
Subsequently, the coordinate value of the coordinate input by the tablet pen 103 is detected at predetermined time intervals, and the pressure when the coordinate is input is detected (step S602). Since the writing brush drawing apparatus 100 uses the tablet 150, the tablet 150 can detect information on coordinates and pressure. Next, the moving direction of the tablet pen 103 is calculated from the locus of coordinate values, and the orientation (writing tip direction) of the drawing pattern is determined (step S603). At the time of determination, it is oriented with a predetermined inertia toward the direction opposite to the moving direction of the tablet pen 103. Specifically, a process of reducing the rotation amount of the rotation angle as the moving speed of the tablet pen 103 decreases.
[0104]
Subsequently, it is determined whether or not the direction of the input coordinates has suddenly turned (step S604). If it is determined that the direction has suddenly turned, processing for reducing the length portion of the drawing pattern is performed (step S605). By passing through step S603, step S604, and step S605, an unnatural protrusion is not expressed in the quadruple portion or the folded portion of the character being drawn, and a natural writing brush drawing texture can be obtained.
[0105]
Finally, a drawing pattern is sequentially drawn at each sampling point (step S606). The drawing pattern to be drawn on the sampling point is appropriately changed according to various conditions based on the initial image of the drawing mode determined in step S601. Specifically, according to the writing pressure and speed of the tablet pen 103, the number, size, and shading of the grayscale images constituting the drawing pattern are adjusted. In particular, in the thin ink brush mode, smoothing processing is sequentially performed according to the stop time of the tablet pen 103, and a drawing pattern in which ink droplets blur is drawn.
[0106]
Each functional unit described above can be realized as a computer program. That is, the computer system can function as means for realizing each functional unit. FIG. 19 to FIG. 24 are diagrams showing screen configuration examples when the processing result of the computer program is displayed on the display device 104. Among the screen configurations, a “file” menu 701 is a menu for performing basic operations such as opening, closing, and creating a new file. Further, the “brush” menu 702 is a menu for performing each drawing mode, eraser mode, and custom setting described later shown in FIGS. 19 to 24.
[0107]
In addition, the “background” menu is a menu for setting a background, and for example, a half-paper (plain), drawing paper, and canvas can be set. FIG. 25 is a diagram showing an example of a background of drawing paper, and FIG. 26 is a diagram showing an example of a background of canvas. As shown in the figure, in each background example, a constant gray image different from a plain half-paper is formed, and drawing textures in consideration of the background can be obtained by overlapping the drawing patterns. In actual drawing, the surface irregularities may appear in the front in watercolor paintings and oil paintings. However, the brush brush drawing apparatus 100 does not employ ink paintings on a canvas, for example, drawing unique to a computer system, which is not adopted in actual combinations. It is also possible to obtain a texture.
[0108]
A “color selection” menu 704 is a menu for selecting various drawing colors. Therefore, in the brushstroke drawing, an unprecedented ink painting expression other than black becomes possible. An “erase” menu 705 is a menu for erasing all characters and diagrams drawn on the drawing screen 706.
[0109]
Next, the characteristic (P) of the “brush” menu 702 will be described. Allows custom setting of various brushstroke parameters. FIG. 27 is a diagram showing an example of a setting screen for customizing the size of the drawing pattern. As shown in the figure, the length of the drawing pattern, the width of the root, and the width of the tip can be changed. FIG. 28 is a diagram showing an example of a setting screen for customizing a grayscale image or the like. As shown in the figure, the composition ratio of the texture pattern and the drawing pattern, the correction amount of the point density, the adjustment of the inertia m, and the reference value for determining the rotation of the tablet pen 103 can be changed. The composition ratio of the texture pattern and the drawing pattern represents the composition ratio of the unevenness or shading (texture) of the background and the shading of the drawing pattern.
[0110]
FIG. 29 is a diagram illustrating an example of a setting screen for customizing ink (inking ink). As shown in the figure, it is possible to change the amount of ink, the presence or absence of a blur due to writing pressure, the presence or absence of a blur due to the speed of a brush, the amount of blur due to speed, and the amount of blur. FIG. 30 is a diagram showing an example of a setting screen for customizing the density and contrast. FIG. 31 is a diagram illustrating an example of a setting screen for customizing the amount of penetration and the delay control. Note that delay control realizes a function that automatically roughens the interpolation and prevents the drawing from following the movement of the pen when a situation occurs in which the drawing ability of the personal computer is low and the drawing cannot catch up. Refers to control.
[0111]
By appropriately programming each functional unit described above and installing it in a computer system including the tablet 150, the computer can be operated as a writing brush drawing device. The distribution mode of the program is not limited to a recording medium such as a CD-ROM, but can be distributed through an electric line such as the Internet.
[0112]
【The invention's effect】
As described above, the writing brush drawing apparatus according to the present invention (Claim 1) allows the drawing pattern to be gently changed in the portion of “character” to be drawn or “kad” of the diagram, and in addition, faint expression can be easily performed. Thus, it is possible to reproduce a natural brushstroke drawing with a good texture using a tablet.
[0113]
In addition, the brush writing device of the present invention (Claim 2) prevents unnecessary protrusion drawing due to a drawing pattern in steep folding drawing such as “splash”, and thus, using a tablet, This makes it possible to reproduce brushstrokes with good texture.
[0114]
Moreover, the brush writing apparatus of the present invention (Claim 3) is capable of blurring expression, whereby natural brush writing can be reproduced with good texture using a tablet.
[0115]
In addition, the brush writing device of the present invention (Claim 4) prevents unnecessary protrusion drawing due to a drawing pattern in steep folding drawing such as “splash”, and thus, using a tablet, This makes it possible to reproduce brushstrokes with good texture.
[0116]
  In addition, the brush writing apparatus of the present invention (Claim 5) can perform dynamic blur expression, thereby reproducing natural brush writing with good texture using a tablet.
[0117]
In addition, the writing brush drawing program of the present invention (Claim 6) allows the drawing pattern to change direction gently at the “Kado” portion of the character or diagram to be drawn, and in addition, faint expression can be easily performed. It is possible to reproduce a natural writing brush with good texture using a tablet.
[0118]
In addition, the writing brush drawing program of the present invention (Claim 7) prevents unnecessary protrusion drawing due to a drawing pattern in steep folding drawing such as “splash”, thereby enabling natural use of a tablet. This makes it possible to reproduce brushstrokes with good texture.
[0119]
In addition, the writing brush drawing program of the present invention (claim 8) enables blurring expression, thereby reproducing natural writing brush drawing with good texture using a tablet.
[0120]
Further, the writing brush drawing program of the present invention (Claim 9) prevents unnecessary protrusion drawing due to a drawing pattern in steep folding drawing such as “splash”, and thus a natural use of a tablet. This makes it possible to reproduce brushstrokes with good texture.
[0121]
  In addition, the writing brush drawing program of the present invention (claim 10) enables dynamic blurring expression, thereby enabling natural writing brush drawing to be reproduced with good texture using a tablet.
[0122]
In addition, the brush writing method of the present invention (claim 11) enables blurring expression, thereby enabling natural brush brush drawing to be reproduced with good texture using a tablet.
[0123]
Further, the brush writing method of the present invention (Claim 12) prevents unnecessary protrusion drawing due to a drawing pattern in steep folding drawing such as “splash”, and this makes it possible to use a tablet in a natural manner. This makes it possible to reproduce brushstrokes with good texture.
[0124]
  In addition, the brush writing method of the present invention (Claim 13) enables dynamic blurring expression, thereby enabling natural brush brush drawing to be reproduced with a good texture using a tablet.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an example of an overview configuration of a brush writing apparatus according to the present invention.
FIG. 2 is an explanatory diagram showing a configuration example of a tablet (tablet plate and tablet pen).
FIG. 3 is a diagram illustrating an external configuration of a liquid crystal pen tablet in which a coordinate input surface and a display device are integrally configured.
FIG. 4 is an explanatory diagram showing an example of a hardware configuration of the brush writing apparatus according to the present invention.
FIG. 5 is an explanatory diagram showing an example of a functional configuration that regulates the trajectory of writing brush in the writing brush drawing apparatus according to the present embodiment;
FIG. 6 is an explanatory diagram showing a relationship between a drawing pattern and a writing pressure (pressure value).
FIG. 7 is an explanatory diagram for defining each variable for creating a drawing pattern.
FIG. 8 shows the relationship between the orientation θ of the drawing pattern and the moving direction of the tablet pen.
FIG. 9 is a drawing conceptual diagram showing unnatural protrusion drawing in a caddy and the direction of a drawing pattern when inertia is controlled.
FIG. 10 is a diagram illustrating an example of unnatural protrusion drawing that appears when the tablet pen is suddenly turned.
FIG. 11 is an explanatory diagram showing an example of a functional configuration for changing an expression in a drawing pattern in the writing brush drawing apparatus according to the present embodiment;
FIG. 12 is a diagram showing an example of a drawing pattern employed in the writing brush drawing apparatus and a grayscale image (enlarged view) inside the drawing pattern.
FIG. 13 is a diagram illustrating a state in which blur is propagated by sequentially performing a smoothing process on a drawing pattern.
FIG. 14 is a diagram showing a shadow pattern and a drawing example.
FIG. 15 is a diagram illustrating a drawing example of a writing brush drawing apparatus.
FIG. 16 is a diagram showing examples of brushstroke drawing in various drawing modes.
17 is a chart displaying parameters of various drawing modes shown in FIG.
FIG. 18 is a flowchart illustrating a processing flow of the writing brush drawing apparatus.
FIG. 19 is a diagram illustrating an example of a screen configuration when a processing result of a computer program is displayed on a display device.
FIG. 20 is a diagram illustrating a screen configuration example when a processing result of a computer program is displayed on a display device.
FIG. 21 is a diagram illustrating a screen configuration example when a processing result of a computer program is displayed on a display device.
FIG. 22 is a diagram showing a screen configuration example when a processing result of a computer program is displayed on a display device.
FIG. 23 is a diagram showing a screen configuration example when a processing result of a computer program is displayed on a display device.
FIG. 24 is a diagram showing a screen configuration example when a processing result of a computer program is displayed on a display device.
FIG. 25 is a diagram illustrating an example of a background of an image paper.
FIG. 26 is a diagram showing an example of a canvas background.
FIG. 27 is a diagram illustrating an example of a setting screen for customizing the size of a drawing pattern.
FIG. 28 is a diagram illustrating an example of a setting screen for customizing a grayscale image and the like.
FIG. 29 is a diagram illustrating an example of a setting screen for customizing ink.
FIG. 30 is a diagram illustrating an example of a setting screen for customizing density and contrast.
FIG. 31 is a diagram showing an example of a setting screen for customizing the amount of penetration and delay control.
[Explanation of symbols]
100 writing brush drawing device
101 Main unit
102 tablet board
103 tablet pen
104 Display device
105 keyboard
106 mice
121 Coordinate input surface
122 pen stand
123 Transmission line
131 Pen tip
132 Eraser part
133,134 Side switch
150 tablets
401 CPU
402 ROM
403 RAM
404 Hard disk (HD)
405 graphics card
441 OS
442 Writing brush drawing software
443 Driver software
501 Coordinate input part
502 Coordinate value detection unit
503 Pressure detector
504 Drawing pattern scaling unit
505 Movement direction calculation unit
506 Drawing pattern rotation unit
507 Distance interval calculation unit
508 Rotation control unit
509 Turn determination unit
510 Drawing pattern shortener
511 Drawing unit
512 Gray image adjustment unit
513 Stop determination section
514 Smoothing unit
515 Stop count counter
516 Smoothing control unit

Claims (13)

A writing brush drawing apparatus including a tablet having a coordinate input surface and coordinate input means for inputting coordinates to the coordinate input surface, and performing drawing according to a drawing pattern trajectory that is a basic shape of drawing,
Applying a smoothing filter to a plurality of black spot images that are randomly distributed in the drawing pattern, the drawing pattern is constituted by a gray-scale image in which the drawing color becomes lighter as the distance from the image increases.
Coordinate value detection means for detecting the coordinate value of the coordinate input by the coordinate input means at predetermined time intervals;
Pressure detection means for detecting pressure when the coordinate input means is inputting coordinates to the coordinate input surface;
Enlarging / reducing means for enlarging or reducing the size of the drawing pattern according to the pressure detected by the pressure detecting means;
A moving direction calculating means for calculating a moving direction of the coordinate input means based on the coordinate values sequentially detected by the coordinate value detecting means;
A drawing pattern rotating means for rotating the drawing pattern so that a writing tip portion of the drawing pattern faces in a direction opposite to the moving direction calculated by the moving direction calculating means;
A distance interval calculating means for calculating adjacent distance intervals of the coordinate values sequentially detected by the coordinate value detecting means;
Rotation control means for controlling the drawing pattern rotation means based on the distance interval of the coordinate values calculated by the distance interval calculation means, and for reducing the rotation amount of the drawing pattern;
According to the pressure detected by the pressure detection means and / or according to the distance interval of the coordinate values determined by the distance interval calculation means, the number of grayscale images and / or the size of the grayscale image and / or the grayscale. A grayscale image adjusting means for adjusting the grayscale of the image;
The drawing pattern rotated by the drawing pattern rotation unit and the rotation control unit, enlarged or reduced by the enlargement / reduction unit, and adjusted by the grayscale image adjustment unit is sequentially applied to the coordinate position detected by the coordinate value detection unit. A drawing means for drawing;
A brush writing apparatus comprising: A turning determination means for determining whether or not the moving direction calculated by the moving direction calculation means has suddenly turned;
A pattern shortening means for shortening the length of the writing pattern by the predetermined drawing number or the predetermined drawing distance when it is determined by the turning determination means that the moving direction has suddenly turned; and
With
The drawing means is rotated by the drawing pattern rotating means and the rotation control means, enlarged or reduced by the enlargement / reduction means, adjusted by the grayscale image adjusting means, and shortened by the pattern shortening means. 2. The writing brush drawing apparatus according to claim 1, wherein the drawn pattern is sequentially drawn at the coordinate position detected by the coordinate value detecting means. A writing brush drawing apparatus including a tablet having a coordinate input surface and coordinate input means for inputting coordinates to the coordinate input surface, and performing drawing according to a drawing pattern trajectory that is a basic shape of drawing,
Coordinate value detection means for detecting the coordinate value of the coordinate input by the coordinate input means at predetermined time intervals;
Pressure detection means for detecting pressure when the coordinate input means is inputting coordinates to the coordinate input surface;
Enlarging / reducing means for enlarging or reducing the size of the drawing pattern according to the pressure detected by the pressure detecting means;
A moving direction calculating means for calculating a moving direction of the coordinate input means based on the coordinate values sequentially detected by the coordinate value detecting means;
A drawing pattern rotating means for rotating the drawing pattern so that a writing tip portion of the drawing pattern faces in a direction opposite to the moving direction calculated by the moving direction calculating means;
A distance interval calculating means for calculating adjacent distance intervals of the coordinate values sequentially detected by the coordinate value detecting means;
Rotation control means for controlling the drawing pattern rotation means based on the distance interval of the coordinate values calculated by the distance interval calculation means, and for reducing the rotation amount of the drawing pattern;
A stop determining means for determining whether or not the coordinate input means is stopped based on the coordinate value detected by the coordinate value detecting means;
Smoothing means for applying a smoothing process to the drawing pattern when the stop determination means determines that the coordinate input means is stopped;
The drawing pattern rotated by the drawing pattern rotation unit and the rotation control unit, enlarged or reduced by the enlargement / reduction unit, and smoothed by the smoothing unit is sequentially placed at the coordinate position detected by the coordinate value detection unit. A drawing means for drawing;
A brush writing apparatus comprising: A turning determination means for determining whether or not the moving direction calculated by the moving direction calculation means has suddenly turned;
A pattern shortening means for shortening the length of the writing pattern by the predetermined drawing number or the predetermined drawing distance when it is determined by the turning determination means that the moving direction has suddenly turned; and
With
The drawing means is rotated by the drawing pattern rotating means and the rotation control means, enlarged or reduced by the enlargement / reduction means, smoothed by the smoothing means, and shortened by the pattern shortening means. 4. The writing brush drawing apparatus according to claim 3, wherein the drawn pattern is sequentially drawn at the coordinate position detected by the coordinate value detecting means. A number-of-stops counting unit that counts the number of times that the coordinate input unit is determined to be stopped at the same place by the stop determination unit;
Smoothing control means for controlling the smoothing means in accordance with the number of times counted by the stationary number counting means to increase the diffusion parameter of the smoothing process;
With
5. The writing brush drawing apparatus according to claim 3, wherein the drawing unit further draws a smoothed drawing pattern under the control of the smoothing control unit. A program for drawing a drawing pattern, which is a basic shape of drawing, according to the locus using an output signal from a tablet having a coordinate input surface and coordinate input means for inputting coordinates to the coordinate input surface,
The drawing pattern is composed of a grayscale image in which the drawing color becomes lighter as the distance from the center is increased by applying a smoothing filter to a plurality of black spot images randomly distributed in the drawing pattern.
Computer
Coordinate value detection means for detecting the coordinate value of the coordinate input by the coordinate input means at predetermined time intervals;
Pressure detection means for detecting pressure when the coordinate input means is inputting coordinates to the coordinate input surface;
Enlarging / reducing means for enlarging or reducing the size of the drawing pattern according to the pressure detected by the pressure detecting means;
A moving direction calculating means for calculating a moving direction of the coordinate input means based on the coordinate values sequentially detected by the coordinate value detecting means;
A drawing pattern rotating means for rotating the drawing pattern so that a writing tip portion of the drawing pattern faces in a direction opposite to the moving direction calculated by the moving direction calculating means;
A distance interval calculating means for calculating adjacent distance intervals of the coordinate values sequentially detected by the coordinate value detecting means;
Rotation control means for controlling the drawing pattern rotation means based on the distance interval of the coordinate values calculated by the distance interval calculation means, and for reducing the rotation amount of the drawing pattern;
According to the pressure detected by the pressure detection means and / or according to the distance interval of the coordinate values determined by the distance interval calculation means, the number of grayscale images and / or the size of the grayscale image and / or the grayscale. A grayscale image adjusting means for adjusting the grayscale of the image;
The drawing pattern rotated by the drawing pattern rotation unit and the rotation control unit, enlarged or reduced by the enlargement / reduction unit, and adjusted by the grayscale image adjustment unit is sequentially applied to the coordinate position detected by the coordinate value detection unit. A writing brush drawing program which functions as a drawing means for drawing. In addition, the computer
A turning determination means for determining whether or not the moving direction calculated by the moving direction calculation means has suddenly turned;
When it is determined by the turning determination means that the moving direction has suddenly turned, it functions as a pattern shortening means that shortens the length of the drawing pattern brush tip by a predetermined drawing number or a predetermined drawing distance;
The drawing means is rotated by the drawing pattern rotation means and the rotation control means, enlarged or reduced by the enlargement / reduction means, adjusted by the grayscale image adjustment means, and shortened by the pattern shortening means. 7. The writing brush drawing program according to claim 6, wherein the drawn pattern is sequentially drawn at the coordinate position detected by the coordinate value detecting means. A program for drawing a drawing pattern, which is a basic shape of drawing, according to the locus using an output signal from a tablet having a coordinate input surface and coordinate input means for inputting coordinates to the coordinate input surface,
Computer
Coordinate value detection means for detecting the coordinate value of the coordinate input by the coordinate input means at predetermined time intervals;
Pressure detection means for detecting pressure when the coordinate input means is inputting coordinates to the coordinate input surface;
Enlarging / reducing means for enlarging or reducing the size of the drawing pattern according to the pressure detected by the pressure detecting means;
A moving direction calculating means for calculating a moving direction of the coordinate input means based on the coordinate values sequentially detected by the coordinate value detecting means;
A drawing pattern rotating means for rotating the drawing pattern so that a writing tip portion of the drawing pattern faces in a direction opposite to the moving direction calculated by the moving direction calculating means;
A distance interval calculating means for calculating adjacent distance intervals of the coordinate values sequentially detected by the coordinate value detecting means;
Rotation control means for controlling the drawing pattern rotation means based on the distance interval of the coordinate values calculated by the distance interval calculation means, and for reducing the rotation amount of the drawing pattern;
A stop determining means for determining whether or not the coordinate input means is stopped based on the coordinate value detected by the coordinate value detecting means;
Smoothing means for applying a smoothing process to the drawing pattern when the stop determination means determines that the coordinate input means is stopped;
The drawing pattern rotated by the drawing pattern rotation unit and the rotation control unit, enlarged or reduced by the enlargement / reduction unit, and smoothed by the smoothing unit is sequentially applied to the coordinate position detected by the coordinate value detection unit. A writing brush drawing program which functions as a drawing means for drawing. In addition, the computer
A turning determination means for determining whether or not the moving direction calculated by the moving direction calculation means has suddenly turned;
When it is determined by the turning determination means that the moving direction has suddenly turned, it functions as a pattern shortening means that shortens the length of the drawing pattern brush tip by a predetermined drawing number or a predetermined drawing distance;
The drawing means is rotated by the drawing pattern rotation means and the rotation control means, enlarged or reduced by the enlargement / reduction means, smoothed by the smoothing means, and shortened by the pattern shortening means. 9. The writing brush drawing program according to claim 8, wherein the drawn pattern is sequentially drawn at the coordinate position detected by the coordinate value detecting means. In addition, the computer
A number-of-stops counting unit that counts the number of times that the coordinate input unit is determined to be stopped at the same place by the stop determination unit;
According to the number of times counted by the stationary number counting means, the smoothing means is controlled to function as a smoothing control means for increasing the diffusion parameter of the smoothing process,
10. The writing brush drawing program according to claim 8, wherein the drawing means further functions to draw a drawing pattern smoothed under the control of the smoothing control means. 11. A writing brush drawing method applied to a writing brush drawing apparatus including a tablet having a coordinate input surface and coordinate input means for inputting coordinates to the coordinate input surface and performing drawing according to a drawing pattern trajectory that is a basic drawing shape. And
A coordinate value detection step of detecting the coordinate value of the coordinate input by the coordinate input means at predetermined time intervals;
A pressure detecting step of detecting pressure when inputting coordinates to the coordinate input surface in the coordinate input step;
An enlargement / reduction step of enlarging or reducing the size of the drawing pattern according to the pressure detected in the pressure detection step;
A moving direction calculating step of calculating a moving direction of the coordinate input means based on the coordinate values sequentially detected in the coordinate value detecting step;
A drawing pattern rotation step of rotating the drawing pattern so that a writing tip portion of the drawing pattern faces in a direction opposite to the movement direction calculated in the movement direction calculation step;
A distance interval calculating step of calculating adjacent distance intervals of the coordinate values sequentially detected in the coordinate value detecting step;
A rotation control step of controlling a rotation process in the drawing pattern rotation step based on a distance interval of coordinate values in the distance interval calculation step to reduce a rotation amount of the drawing pattern;
A stop determination step of determining whether or not the coordinate input means is stopped based on the coordinate value detected in the coordinate value detection step;
A smoothing step of performing a smoothing process on the drawing pattern when the coordinate input means is determined to be stopped in the stop determination step;
The coordinate position detected in the coordinate value detection step is the drawing pattern rotated through the drawing pattern rotation step and the rotation control step, enlarged or reduced through the enlargement / reduction step, and smoothed by the smoothing step. A drawing process of sequentially drawing in
A brushstroke drawing method characterized by comprising A turning determination step for determining whether or not the moving direction calculated in the moving direction calculation step has suddenly turned; and
A pattern shortening step of shortening the length of the brush tip of the drawing pattern by a predetermined drawing number or a predetermined drawing distance when it is determined that the moving direction has suddenly turned in the turning determination step;
Including
The drawing process is rotated through the drawing pattern rotation process and the rotation control process, is enlarged or reduced through the enlargement / reduction process, is smoothed through the smoothing process, is passed through the pattern shortening process, and is 12. The writing brush drawing apparatus according to claim 11, wherein the drawing pattern whose length is shortened is sequentially drawn at the coordinate position detected in the coordinate value detecting step. A number-of-stops counting step for counting the number of times the coordinate input means is determined to be stopped at the same place in the stop determination step;
A smoothing control step of controlling a smoothing process in the smoothing step and increasing a diffusion parameter of the smoothing process according to the number of times counted in the stationary number counting step;
Including
The brush drawing method according to claim 11 or 12, wherein in the drawing step, a drawing pattern smoothed under the control of the smoothing control step is drawn.

Images