JPH06261206A - Image processor - Google Patents
Image processorInfo
- Publication number
- JPH06261206A JPH06261206A JP5070821A JP7082193A JPH06261206A JP H06261206 A JPH06261206 A JP H06261206A JP 5070821 A JP5070821 A JP 5070821A JP 7082193 A JP7082193 A JP 7082193A JP H06261206 A JPH06261206 A JP H06261206A
- Authority
- JP
- Japan
- Prior art keywords
- sub
- variable power
- scaling
- scanning
- main
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000008030 elimination Effects 0.000 abstract 1
- 238000003379 elimination reaction Methods 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 9
- 238000000034 method Methods 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 2
- 230000035939 shock Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T3/00—Geometric image transformations in the plane of the image
- G06T3/40—Scaling of whole images or parts thereof, e.g. expanding or contracting
- G06T3/4007—Scaling of whole images or parts thereof, e.g. expanding or contracting based on interpolation, e.g. bilinear interpolation
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- Image Input (AREA)
- Image Processing (AREA)
- Editing Of Facsimile Originals (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、画像処理装置、より詳
細には、主走査変倍及び副走査変倍を画像処理にて行う
画像処理装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus, and more particularly to an image processing apparatus for performing main scanning scaling and sub scanning scaling by image processing.
【0002】[0002]
【従来の技術】画像データの変倍処理(解像度変換とも
呼ばれる)は、通常、主走査方向での変倍処理と、副走
査方向での変倍処理の2系統の処理に分けて行なってい
る。そして、従来より、ディジタル複写機においては、
主走査変倍は、画像処理回路で実行され、他方、副走査
方向の変倍処理は、スキャナのスピードを倍率に応じて
切り換えることで実行している。2. Description of the Related Art Image data scaling processing (also referred to as resolution conversion) is usually divided into two systems, a scaling processing in the main scanning direction and a scaling processing in the sub-scanning direction. . And, conventionally, in the digital copying machine,
The main scanning scaling is performed by the image processing circuit, while the scaling processing in the sub-scanning direction is performed by switching the speed of the scanner according to the magnification.
【0003】[0003]
【発明が解決しようとする課題】副走査方向の変倍処理
をスキャナのスキャンスピードを切り換えて行なうこと
は、倍率Nに対し、スキャンスピードを1/N倍の速度
に設定する(倍率0.25のとき、スキャンスピードは
4倍となる)必要があり、モータパワーを大きくしなけ
ればならなくなる。また、倍率の設定値が等倍1に対
し、著しく離れた値となるとき、例えば、倍率が0.0
5倍の縮小のとき、スキャンスピードは20倍となり、
これはモータパワーが著しく大きくなるだけでなく、限
られたスペース内でメカ機構を往復動させるため、衝
動、衝撃が大きく、通常、実現不可能に近い。また、倍
率が20倍の拡大のとき、スキャンスピードは0.05
倍となり、スキャナのメカ機構を等倍時の速度に対して
このように超低速でスムースに回転制御することは、ス
テッピングモータを使用する等の特別の配慮を行なわな
いと実現できない。To perform the variable magnification processing in the sub-scanning direction by switching the scan speed of the scanner, the scan speed is set to 1 / N times the magnification N (magnification 0.25). In that case, the scan speed must be four times higher), and the motor power must be increased. Also, when the set value of the magnification is a value that is significantly different from the unity magnification of 1, for example, the magnification is 0.0
At 5 times reduction, the scan speed becomes 20 times,
This not only increases the motor power remarkably, but also causes the mechanical mechanism to reciprocate within a limited space, resulting in large impulses and shocks, which is usually not possible. When the magnification is 20 times, the scan speed is 0.05.
It is not possible to control the mechanical mechanism of the scanner smoothly at such an ultra-low speed with respect to the speed at the same magnification, without special consideration such as using a stepping motor.
【0004】[0004]
【課題を解決するための手段】本発明は、上述の課題を
解決するために、主走査変倍及び副走査変倍を画像処理
にて行う画像処理装置において、拡大変倍時、主走査変
倍処理に先だち、副走査変倍処理を行なうことを特徴と
したものである。SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an image processing apparatus for performing main scanning scaling and sub-scanning scaling by image processing. It is characterized in that the sub-scanning variable magnification processing is performed prior to the double processing.
【0005】[0005]
【作用】ディジタル複写機での変倍処理を、主走査変倍
及び副走査変倍のいずれをも画像処理のみで実行するこ
とにより、機械的な要因により発生する倍率の設定範囲
の限界を解消する。By performing the scaling process in the digital copying machine by performing only the main scanning scaling and the sub-scanning scaling only with the image processing, the limit of the range of the scaling factor caused by mechanical factors is solved. To do.
【0006】[0006]
【実施例】変倍の方法は種々提案されているが、以下に
説明する本発明の実施例においては、近接2画素のデー
タより、必要とする画素位置での画素濃度を直線近似で
求めるものとする。Various methods of scaling have been proposed, but in the embodiments of the present invention described below, the pixel density at a required pixel position is obtained by linear approximation from the data of two adjacent pixels. And
【0007】図2は、本発明の動作原理を説明するため
の図で、図2において、縦軸は濃度値、横軸は画素位置
を示し、主走査方向の画素位置a1,b1及び補間位置Y
1より予測される補間位置Y1での画像濃度(Y)を次式
より算出する。 濃度(Y)=濃度(a)+{濃度(b)−濃度(a)}
×x ここで、xは、画素位置a1から画素位置Y1の距離を示
すものであり、1以下の量子化された小数である。ま
た、画素a1から画素b1の距離を1とするものである。FIG. 2 is a diagram for explaining the operating principle of the present invention. In FIG. 2, the vertical axis represents the density value, the horizontal axis represents the pixel position, and pixel positions a 1 , b 1 in the main scanning direction and Interpolation position Y
Image density interpolation position Y 1 to be predicted than 1 (Y) is calculated from the following equation. Density (Y) = density (a) + {density (b) -density (a)}
Xx Here, x indicates the distance from the pixel position a 1 to the pixel position Y 1 , and is a quantized decimal number of 1 or less. Further, the distance from the pixel a 1 to the pixel b 1 is 1.
【0008】倍率Nが決定されると、次のように補間位
置のピッチを算出する。 ピッチ=1/N 補間位置は、常に、 Yn=Yn-1+ピッチ=Yn-1+1/N と表現可能である。補間位置Ynが決まれば、Ynを挟
む隣接2画素のデータより、同様にして画素データ 濃度(Y)=濃度(a)+{濃度(b)−濃度(a)}
×x の一般式が算出される。When the magnification N is determined, the pitch of the interpolation position is calculated as follows. Pitch = 1 / N The interpolation position can always be expressed as Yn = Y n-1 + pitch = Y n-1 + 1 / N. When the interpolation position Yn is determined, pixel data is similarly obtained from the data of two adjacent pixels sandwiching Yn. Density (Y) = density (a) + {density (b) -density (a)}
A general formula of xx is calculated.
【0009】図1は、上述のアルゴリズムに基いた変倍
部のブロック図で、図中、1は副走査変倍部、2は主走
査変倍部で、まず、副走査変倍を行う。ここで、副走査
変倍は、1本のラインバッファ3を用い、副走査方向で
の2つの隣接画素データA,Bより補間位置Ynでの補
間データを演算し、その結果を、主走査変倍用ラッチ4
へ出力する。主走査変倍部2では、ラッチの前後の入力
a,b、すなわち、主走査方向での隣接2画素a,bの
濃度データより、主走査方向での補間データYを演算
し、その結果を出力する。FIG. 1 is a block diagram of a scaling unit based on the above-described algorithm. In the figure, 1 is a sub-scanning scaling unit, and 2 is a main-scanning scaling unit. First, sub-scanning scaling is performed. Here, in the sub-scanning scaling, one line buffer 3 is used to calculate interpolation data at the interpolation position Yn from two adjacent pixel data A and B in the sub-scanning direction, and the result is changed to the main scanning scaling. Double latch 4
Output to. In the main scanning magnification changing unit 2, interpolation data Y in the main scanning direction is calculated from the inputs a and b before and after the latch, that is, the density data of two adjacent pixels a and b in the main scanning direction, and the result is calculated. Output.
【0010】なお、以上に隣接2画素のデータより、補
間データを演算する例について説明したが、隣接の画素
数は一般にN画素まで拡大の解釈が可能であり、Nが大
きい程、複雑な補間が可能となり、補間値の精度が向上
する。Although an example in which the interpolation data is calculated from the data of two adjacent pixels has been described above, the number of adjacent pixels can generally be expanded to N pixels, and the larger N is, the more complicated interpolation is performed. The accuracy of the interpolation value is improved.
【0011】次に、副走査演算を、主走査演算処理の前
に実行する理由について説明する。図3は、画像の入力
と出力の各サイズを示したもので、図(a)が変倍への
入力画像、図(b)が出力画像とする。変倍値は独立変
倍をも考慮し、主走査変倍値をN、副走査変倍値をMと
する。従って、変倍前の画素数をL,ライン数をKとす
れば変倍後の画素数はL×N、ライン数はK×Mとな
る。Next, the reason why the sub-scan calculation is executed before the main-scan calculation processing will be described. 3A and 3B show respective sizes of input and output of an image. FIG. 3A is an input image for scaling and FIG. 3B is an output image. In consideration of independent scaling, the scaling value is set to N for the main scanning scaling value and M for the sub-scanning scaling value. Therefore, if the number of pixels before scaling is L and the number of lines is K, the number of pixels after scaling is L × N and the number of lines is K × M.
【0012】図4は、入力画像(a)に対して、最初に
主走査変倍(b)を行い、その後に副走査変倍の(c)
を行った場合を示す。この場合、主走査変倍により、ま
ず、主走査の画素数が、L×Nに増加する(もちろんN
>1の拡大時)。従って、次に続く副走査変倍のライン
バッファは、図1において、ラインバッファ3に当る
が、このラインバッファのメモリ容量として、L×Nの
画素数で決まる値を確保する必要があり、倍率Nの最大
値で決まる画素数を最大画素数として考慮しなければな
らない。In FIG. 4, an input image (a) is first subjected to main scanning scaling (b) and then subjected to sub scanning scaling (c).
The following shows the case. In this case, the number of pixels in the main scanning first increases to L × N due to the main scanning scaling (N is of course N.
> 1 magnification). Therefore, the following line buffer for sub-scanning scaling corresponds to the line buffer 3 in FIG. 1, but it is necessary to secure a value determined by the number of pixels L × N as the memory capacity of this line buffer, and the magnification The number of pixels determined by the maximum value of N must be considered as the maximum number of pixels.
【0013】図5は、入力画像(a)に対して副走査変
倍(c)を先に実行し、次で主走査変倍(b)を実行す
る、本発明の方法を示す図で、この方法でのラインバッ
ファの容量は、副走査変倍(c)をしても、主走査の画
素数が増加しないため、入力の主走査方向の画素数Lで
決定されているため、主走査変倍(b)を先に行う場合
に比して、L×N−L=L(N−1)の画素数分、ライ
ンバッファ3の容量を少なく出来る。以上に、隣接2画
素の濃度データより変倍を行う場合の実施例について説
明したが、これは、隣接N画素の場合でも同じ考えであ
り、変倍に当って、まず、副走査変倍を行い、その後
に、主走査変倍を行なうのが、ハードウエアの負担を少
なく出来ることが分る。FIG. 5 is a diagram showing the method of the present invention in which the sub-scanning scaling (c) is first performed on the input image (a) and then the main-scanning scaling (b) is performed. The capacity of the line buffer in this method is determined by the number of pixels L in the main scanning direction of the input because the number of pixels in the main scanning does not increase even if the sub scanning scaling (c) is performed. The capacity of the line buffer 3 can be reduced by the number of pixels L × N−L = L (N−1), as compared with the case where the scaling (b) is performed first. Although the embodiment in which the scaling is performed based on the density data of the two adjacent pixels has been described above, the same idea is applied to the case of the adjacent N pixels, and in the scaling, first, the sub-scanning scaling is performed. It can be seen that the load on the hardware can be reduced by performing the main scanning scaling after that.
【0014】なお、以上に、ディジタル複写機、DTP
システムでの倍率変換をベースに説明し、本発明は、上
記例に限定されるものではなくFAX(300dpi)
のデータをプリンタ(400dpi)で印字する場合等
に生ずる解像度変換にも適用可能であることを容易に理
解できる。In addition to the above, the digital copying machine, the DTP
The present invention is not limited to the above example, and the description is based on the magnification conversion in the system. FAX (300 dpi)
It can be easily understood that the present invention can be applied to the resolution conversion that occurs when the data of (1) is printed by a printer (400 dpi).
【0015】[0015]
【発明の効果】拡大変倍時、副走査変倍の後、主走査変
倍を行なうようにしたので、使用するメモリを少なくで
きる。また、ディジタル複写機での変倍処理において、
主走査変倍及び副走査変倍のをいずれをも画像処理のみ
で実行するようにしたので機械的な要因より発生する倍
率の設定範囲の限界を解消することができる。スキャナ
の機構動作としては、等倍100%の基準動作のみの動
作で変倍処理が可能であり、同時に、モータパワーも等
倍時のみのパワーで設定可能であり、モータの小型化が
可能となり、更には、モータ速度切り換え回路が不要と
なり、機構制御及び構造のシンプル化を図ることが可能
となる。As described above, during the enlargement / reduction, the main scanning magnification is performed after the sub-scanning magnification, so that the memory used can be reduced. Also, in the scaling process in a digital copying machine,
Since both the main-scanning scaling and the sub-scanning scaling are executed only by the image processing, it is possible to eliminate the limit of the setting range of the magnification caused by a mechanical factor. As for the mechanical operation of the scanner, variable magnification processing can be performed only by the standard operation of 100% normal size, and at the same time, the motor power can be set by the power only at the normal size, which enables downsizing of the motor. Further, the motor speed switching circuit is not required, and the mechanism control and the structure can be simplified.
【図1】本発明による画像処理を実行するのに好適なブ
ロック図の一例を説明するための図である。FIG. 1 is a diagram for explaining an example of a block diagram suitable for executing image processing according to the present invention.
【図2】本発明の動作原理を説明するための図である。FIG. 2 is a diagram for explaining the operation principle of the present invention.
【図3】画像処理(画像の入力と出力のサイズ)の例を
説明するための図である。FIG. 3 is a diagram for explaining an example of image processing (image input and output sizes).
【図4】画像処理の例(主走査変倍→副走査変倍)を説
明するための図である。FIG. 4 is a diagram for explaining an example of image processing (main scanning scaling → sub scanning scaling).
【図5】本発明による画像処理の例(副走査変倍→主走
査変倍)を説明するための図である。FIG. 5 is a diagram for explaining an example of image processing according to the present invention (sub-scanning magnification-> main scanning magnification).
1…副走査変倍部、2…主走査変倍部、3…ラインバッ
ファ、4…ラッチ回路。1 ... Sub-scanning scaling unit, 2 ... Main scanning scaling unit, 3 ... Line buffer, 4 ... Latch circuit.
Claims (1)
て行う画像処理装置において、拡大変倍時、主走査変倍
処理に先だち、副走査変倍処理を行なうことを特徴とす
る画像処理装置。1. An image processing apparatus for performing main-scanning scaling and sub-scanning scaling by image processing, wherein during enlargement scaling, the sub-scanning scaling is performed prior to the main-scanning scaling. Image processing device.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP5070821A JPH06261206A (en) | 1993-03-05 | 1993-03-05 | Image processor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP5070821A JPH06261206A (en) | 1993-03-05 | 1993-03-05 | Image processor |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH06261206A true JPH06261206A (en) | 1994-09-16 |
Family
ID=13442629
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP5070821A Pending JPH06261206A (en) | 1993-03-05 | 1993-03-05 | Image processor |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH06261206A (en) |
-
1993
- 1993-03-05 JP JP5070821A patent/JPH06261206A/en active Pending
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