JP2008153846A - Method and device for correcting color image - Google Patents

Method and device for correcting color image Download PDF

Info

Publication number
JP2008153846A
JP2008153846A JP2006338401A JP2006338401A JP2008153846A JP 2008153846 A JP2008153846 A JP 2008153846A JP 2006338401 A JP2006338401 A JP 2006338401A JP 2006338401 A JP2006338401 A JP 2006338401A JP 2008153846 A JP2008153846 A JP 2008153846A
Authority
JP
Japan
Prior art keywords
color
correction
pixel data
range
unit
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.)
Withdrawn
Application number
JP2006338401A
Other languages
Japanese (ja)
Inventor
Yuji Mizoguchi
裕二 溝口
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kawasaki Microelectronics Inc
Original Assignee
Kawasaki Microelectronics Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Kawasaki Microelectronics Inc filed Critical Kawasaki Microelectronics Inc
Priority to JP2006338401A priority Critical patent/JP2008153846A/en
Publication of JP2008153846A publication Critical patent/JP2008153846A/en
Withdrawn legal-status Critical Current

Links

Images

Landscapes

  • Image Processing (AREA)
  • Facsimile Image Signal Circuits (AREA)
  • Color Image Communication Systems (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the occurrence of any color step when performing color correction with respect to color image data included in a specific color range. <P>SOLUTION: The image quality correction of input color pixel data is carried out, and when performing color correction by correcting again the color pixel data whose image quality correction has been completed when a color to be determined on the basis of the color pixel data is within a specific color range, the color correction is performed again by using a first correction coefficient A1 when the color to be determined on the basis of the color pixel data is within the specific color range, and the color correction is performed again by using a second correction coefficient A2 whose correcting efficiency is smaller than that of the first correction coefficient A1 when the color is within a color range adjacent to the specific color range. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は、画質補正されたカラー画素データを再度補正して色補正を行うカラー画像補正方法および補正装置に関するものである。   The present invention relates to a color image correction method and a correction apparatus that perform color correction by correcting color pixel data whose image quality has been corrected again.

通常各々が８ビットでその濃度（輝度レベル）が表されるカラー画素データＲ，Ｇ，Ｂは、そのカラー画像を表示しあるいは印刷するために、表示装置あるいは印刷装置の特性に応じて画質補正（例えば、特許文献１参照）が行われる。   Color pixel data R, G, and B, each of which is normally 8 bits and represents its density (luminance level), is used to display or print the color image in accordance with the characteristics of the display device or printing device. (For example, refer to Patent Document 1).

この画質補正では、通常、補正特性が予め書き込まれたＬＵＴ（ルックアップテーブル）が使用され、これにカラー画素データを入力させることにより、濃度変換された所望のカラー画素データを出力させることができる。この場合、通常では、Ｒ，Ｇ，Ｂの各カラー画素データについて個々に補正が行われる。   In this image quality correction, normally, an LUT (Look Up Table) in which correction characteristics are written in advance is used, and by inputting color pixel data to this, desired color pixel data whose density has been converted can be output. . In this case, normally, correction is performed individually for each of the R, G, and B color pixel data.

また、補正を行ったカラー画素データに更に補正を加える手法が提案されている（例えば、特許文献２参照）。これによれば、１個のベースＬＵＴから読み出された画素データに対してＲ，Ｇ，Ｂ毎に異なるゲインを乗算して補正を加えることにより、Ｒ，Ｇ，Ｂの各カラー画素データの補正を行うことができる。   In addition, a method of further correcting the corrected color pixel data has been proposed (see, for example, Patent Document 2). According to this, by multiplying the pixel data read from one base LUT by different gains for each of R, G, and B, and adding correction, the R, G, and B color pixel data are corrected. Correction can be performed.

ところが、上記手法はベースＬＵＴに予め決めた一定の係数を乗算するものであり、任意の色について所望の補正を行うことはできなかった。   However, the above method multiplies the base LUT by a predetermined constant coefficient and cannot perform a desired correction for an arbitrary color.

そこで本発明者は、予め決めた特定の色範囲に含まれるカラー画素データについて色補正ができるようにしたカラー画像補正装置を提案した（特願２００５−１９７０７０）。   In view of this, the present inventor has proposed a color image correction apparatus capable of performing color correction on color pixel data included in a predetermined specific color range (Japanese Patent Application No. 2005-197070).

図２はそのカラー画像補正装置の構成を示すブロック図である。１は第１補正部（画質補正部）であり、入力する各８ビットのＲ，Ｇ，Ｂの画素データ毎に設けられた３つの画質補正用のＬＵＴからなる。２Ａは色範囲検出部であり、入力するＲ，Ｇ，Ｂの画素データが予め決めた色範囲に含まれるとき、検出信号Ｓ０を出力する。３Ａは第２補正部（色補正部）であり、色範囲検出部２Ａが検出信号Ｓ０を出力したとき、第１補正部１から出力する画質補正済みのカラー画素データＲ，Ｇ，Ｂに対して、予め設定された共通の補正係数を乗算して色補正を行う。   FIG. 2 is a block diagram showing the configuration of the color image correction apparatus. Reference numeral 1 denotes a first correction unit (image quality correction unit), which includes three LUTs for image quality correction provided for each input 8-bit R, G, B pixel data. Reference numeral 2A denotes a color range detector, which outputs a detection signal S0 when input R, G, B pixel data is included in a predetermined color range. Reference numeral 3A denotes a second correction unit (color correction unit). When the color range detection unit 2A outputs the detection signal S0, the image quality corrected color pixel data R, G, and B output from the first correction unit 1 are output. Thus, color correction is performed by multiplying a preset common correction coefficient.

ここで、赤味がかった色に対してのみ色補正を加えたいときは、例えば、
Ｒ[7:2]≠０、Ｇ「7:3]＝Ｂ「7:3]＝０ (１)
を色範囲検出部２Ａに色範囲として指定しておく。これは、画素データＲの第３〜第８ビットの内のいずれか１ビット以上が「１」で第１〜第２ビットが任意あり、画素データＧとＢの第４〜第８ビットの全部が「０」で第１〜第３ビットが任意であるときである。 Here, when you want to add color correction only to reddish colors, for example,
R [7: 2] ≠ 0, G “7: 3] = B“ 7: 3] = 0 (1)
Is specified as a color range in the color range detection unit 2A. This is because any one or more of the 3rd to 8th bits of the pixel data R is “1”, the 1st to 2nd bits are arbitrary, and all the 4th to 8th bits of the pixel data G and B are all. Is “0” and the first to third bits are arbitrary.

入力カラー画素データＲ，Ｇ，Ｂがこれを満足するときは、色範囲検出部２Ａから検出信号Ｓ０が出力して、第２補正部３Ａにおいて、第１補正部１から出力するカラー画素データＲ，Ｇ，Ｂに対して再度の色補正が行われる。   When the input color pixel data R, G, B satisfies this, the detection signal S0 is output from the color range detection unit 2A, and the color pixel data R output from the first correction unit 1 in the second correction unit 3A. , G, and B are subjected to color correction again.

この色補正の内容としては、例えばカラー画素データＲ，Ｇ，Ｂに対して共通の１を超える補正係数を乗算すれば、赤味がかった画素がより赤っぽい画素となるように色補正が行われる。このときは、純粋な赤の画素のみを対象とする場合と比較して、色範囲検出部２Ａに設定された色範囲の画素を補正の対象とするので、より現実味の高い色補正が行われる。逆に、１未満の補正係数を乗算すれば赤味が薄くなるような補正が行われる。   As the content of this color correction, for example, if the color pixel data R, G, B is multiplied by a common correction coefficient exceeding 1, the color correction is performed so that the reddish pixel becomes a reddish pixel. Done. In this case, compared with the case where only pure red pixels are targeted, since the pixels in the color range set in the color range detection unit 2A are targeted for correction, more realistic color correction is performed. . On the other hand, if the correction coefficient less than 1 is multiplied, the redness is reduced.

このように、予め指定した色範囲に含まれる色を表すカラー画素データＲ，Ｇ，Ｂが入力されたとき、その画素データを補正して所望の色補正を行うことができる。このため、任意の色補正が可能であり、かつ、１個の色を指定して色補正を行う場合と比べて、より実際に即した色補正を実現することが可能となる。
特開２００３−２８８０６０号公報 特開平７−３２２０９６号公報 As described above, when color pixel data R, G, and B representing colors included in a color range designated in advance are input, the pixel data can be corrected to perform desired color correction. For this reason, arbitrary color correction is possible, and more practical color correction can be realized as compared with the case where color correction is performed by designating one color.
JP 2003-288060 A Japanese Patent Laid-Open No. 7-322096

ところが、図２で説明したカラー画像補正装置では、前記指定した色範囲に隣接する色範囲では色補正が行われないので、色補正の後では、指定した色範囲に含まれる色とそれに隣接する色との間に色段差が生じる。また、前記指定した色範囲に無彩色又はこれに近い色範囲が含まれる場合は、当該無彩色又はこれに近い色の場合に、色補正によって着色が行われる。   However, in the color image correction apparatus described with reference to FIG. 2, since color correction is not performed in the color range adjacent to the specified color range, after the color correction, the color included in the specified color range and the adjacent color range are adjacent to the color range. There is a color difference between colors. Further, when the designated color range includes an achromatic color or a color range close thereto, coloring is performed by color correction in the case of the achromatic color or a color close thereto.

本発明の目的は、特定の色範囲に含まれるカラー画素データについて色補正を行う際に、色段差が生ぜず、あるいは無彩色に着色が行われないようにしたカラー画像補正方法および補正装置を提供することである。   An object of the present invention is to provide a color image correction method and a correction apparatus that prevent color steps from being generated or achromatic colors from being generated when color correction is performed on color pixel data included in a specific color range. Is to provide.

上記目的を達成するために、請求項１にかかる発明のカラー画像補正方法は、入力するカラー画素データの画質補正を行い、該画質補正の前又は後のカラー画素データで決まる色が特定の色範囲にあるとき、前記画質補正済みのカラー画素データを再補正して色補正を行うカラー画像補正方法であって、前記画質補正の前又は後のカラー画素データで決まる色が前記特定の色範囲にあるときに、第１の再補正を行い、前記特定の色範囲に隣接する色範囲にあるときに、前記第１の再補正に比較して補正効果が小さい第２の再補正を行うことを特徴とする。
請求項２にかかる発明のカラー画像補正方法は、入力するカラー画素データの画質補正を行い、該画質補正の前又は後のカラー画素データで決まる色が特定の色範囲にあるとき、前記画質補正済みのカラー画素データを再度補正して色補正を行うカラー画像補正方法であって、前記画質補正の前又は後の前記カラー画素データで決まる色が無彩色又はこれに近い色範囲であるときは、前記特定の色範囲にあるときであっても、前記再補正を行わないことを特徴とする。
請求項３にかかる発明のカラー画像補正装置は、入力するカラー画素データの画質補正を行う第１補正部と、該第１補正部の入力側又は出力側のカラー画素データを入力して該カラー画素データで決まる色が特定の色範囲に含まれるとき第１の検出信号を出力する色範囲検出部と、該色範囲検出部が前記第１の検出信号を出力したとき前記第１補正部から出力するカラー画素データを補正する第２補正部とを備えるカラー画像補正装置であって、前記色範囲検出部は、さらに、前記第１補正部の入力側又は出力側のカラー画素データで決まる色が前記特定の色範囲に隣接するとき第２の検出信号を出力し、前記第２補正部は、前記色範囲検出部が前記第１の検出信号を出力したときに、前記第１補正部から出力するカラー画素データに第１の再補正を行い、前記色範囲検出部が前記第２の検出信号を出力したとき、前記第１の再補正よりも補正効果の小さい第２の再補正を行うことを特徴とする。
請求項４にかかる発明のカラー画像補正装置は、入力するカラー画素データの画質補正を行う第１補正部と、該第１補正部の入力側又は出力側のカラー画素データを入力して該カラー画素データで決まる色が特定の色範囲に含まれるとき第１の検出信号を出力する色範囲検出部と、該色範囲検出部が前記第１の検出信号を出力したとき前記第１補正部から出力するカラー画素データを補正する第２補正部とを備えるカラー画像補正装置であって、前記色範囲検出部は、さらに、前記第１補正部の入力側又は出力側のカラー画素データで決まる色が無彩色又はこれに近い色範囲に含まれるとき、第３の検出信号を出力し、前記第２補正部は、前記色範囲検出部が前記第１の検出信号を出力したときであっても、前記色範囲検出部が前記第３の検出信号を出力したときには、前記第２補正部による再補正を行わないことを特徴とする。 In order to achieve the above object, a color image correction method according to a first aspect of the present invention performs image quality correction of input color pixel data, and a color determined by color pixel data before or after the image quality correction is a specific color. A color image correction method for performing color correction by recorrecting the color pixel data after the image quality correction when the color pixel data is within the range, wherein a color determined by the color pixel data before or after the image quality correction is the specific color range The first re-correction is performed, and the second re-correction having a correction effect smaller than that of the first re-correction is performed when it is in a color range adjacent to the specific color range. It is characterized by.
A color image correction method according to a second aspect of the present invention performs image quality correction of input color pixel data, and when the color determined by the color pixel data before or after the image quality correction is in a specific color range, the image quality correction is performed. A color image correction method in which color correction is performed by correcting corrected color pixel data again, and when the color determined by the color pixel data before or after the image quality correction is an achromatic color or a color range close thereto The recorrection is not performed even when the color is in the specific color range.
According to a third aspect of the present invention, there is provided a color image correction apparatus comprising: a first correction unit that performs image quality correction of input color pixel data; and color pixel data on an input side or output side of the first correction unit. When a color determined by the pixel data is included in a specific color range, a color range detection unit that outputs a first detection signal, and when the color range detection unit outputs the first detection signal, from the first correction unit A color image correction apparatus including a second correction unit that corrects color pixel data to be output, wherein the color range detection unit further determines a color determined by color pixel data on an input side or an output side of the first correction unit Is output adjacent to the specific color range, and the second correction unit outputs the first detection signal from the first correction unit when the color range detection unit outputs the first detection signal. The first color pixel data to be output It corrects, when the color range detecting unit has output the second detection signal, and performs a small second recorrecting the correction effect than the first re-corrected.
According to a fourth aspect of the present invention, there is provided a color image correction apparatus comprising: a first correction unit that performs image quality correction of input color pixel data; and color pixel data on an input side or output side of the first correction unit. When a color determined by the pixel data is included in a specific color range, a color range detection unit that outputs a first detection signal, and when the color range detection unit outputs the first detection signal, from the first correction unit A color image correction apparatus including a second correction unit that corrects color pixel data to be output, wherein the color range detection unit further determines a color determined by color pixel data on an input side or an output side of the first correction unit Is included in an achromatic color or a color range close thereto, a third detection signal is output, and the second correction unit is when the color range detection unit outputs the first detection signal. The color gamut detection unit performs the third detection. When outputting signals, characterized in that it does not perform the re-correction by the second correcting unit.

本発明によれば、画質補正の前又は後のカラー画素データで表される色が特定の色範囲に隣接する色範囲に含まれるときは、該特定の色範囲に含まれるときに行われる再補正よりも補正効果の小さい再補正が行われるので、色段差の発生を防止できる。また、前記特定の色範囲に無彩色が含まれる場合は色補正が行われないので、当該無彩色が着色されることを防止できる。   According to the present invention, when the color represented by the color pixel data before or after the image quality correction is included in the color range adjacent to the specific color range, the reproduction performed when the color is included in the specific color range. Since re-correction having a correction effect smaller than that of correction is performed, it is possible to prevent occurrence of a color step. Further, when an achromatic color is included in the specific color range, color correction is not performed, so that the achromatic color can be prevented from being colored.

図１は本発明の１つの実施例のカラー画像補正装置の構成を示すブロック図である。入力する各８ビットのＲ，Ｇ，Ｂの画素データ毎に設けられた３つの画質補正用のＬＵＴからなる第１補正部（画質補正部）１は、前記した図２で説明したものと同じである。   FIG. 1 is a block diagram showing the configuration of a color image correction apparatus according to one embodiment of the present invention. The first correction unit (image quality correction unit) 1 including three LUTs for image quality correction provided for each 8-bit input R, G, B pixel data is the same as that described with reference to FIG. It is.

２は色範囲検出部であり、入力するＲ，Ｇ，Ｂのカラー画素データが、予め決めた色範囲に含まれるとき検出信号Ｓ１を出力する第１検出部２１、該予め決めた色範囲に隣接する色範囲に含まれるとき検出信号Ｓ２を出力する第２検出部２２、該予め決めた色範囲に含まれていて且つ無彩色又はそれに近い色範囲のとき検出信号Ｓ３を出力する第３検出部２３、および検出信号Ｓ１，Ｓ２、Ｓ３に応じて補正係数を選択して出力する選択回路２４からなる。   Reference numeral 2 denotes a color range detection unit. A first detection unit 21 that outputs a detection signal S1 when the input R, G, B color pixel data is included in a predetermined color range. A second detection unit 22 that outputs a detection signal S2 when included in an adjacent color range; and a third detection that outputs a detection signal S3 when included in the predetermined color range and an achromatic color or a color range close thereto. And a selection circuit 24 that selects and outputs a correction coefficient in accordance with the detection signals S1, S2, and S3.

選択回路２４は、検出信号Ｓ１が入力するときは補正係数Ａ１を出力する。この補正係数Ａ１は、色味を強める場合は１を超える値、弱める場合は１未満の値である。また、検出信号Ｓ２が入力するときは、補正係数Ａ１よりも１に近い補正係数Ａ２を出力する。この補正係数Ａ２は、補正係数Ａ１が１を超える値のときは１を超え且つ補正係数Ａ１より小さな値、１未満の値のときは１未満で且つ補正係数Ａ１より大きな値である。つまり、補正係数Ａ２は補正係数Ａ１よりも補正効果の小さい補正係数であり、例えば、Ａ２＝Ａ１／２である。さらに、検出信号Ｓ３が入力されたときは、同時に検出信号Ｓ１が入力されるけれども、補正係数Ａ１はマスクして、補正係数Ａ３（＝１）を出力する。   The selection circuit 24 outputs the correction coefficient A1 when the detection signal S1 is input. The correction coefficient A1 is a value greater than 1 when the color is enhanced, and a value less than 1 when the color is weakened. When the detection signal S2 is input, the correction coefficient A2 closer to 1 than the correction coefficient A1 is output. The correction coefficient A2 is a value that exceeds 1 when the correction coefficient A1 is greater than 1, a value that is smaller than the correction coefficient A1, is less than 1 when the value is less than 1, and is greater than the correction coefficient A1. That is, the correction coefficient A2 is a correction coefficient having a smaller correction effect than the correction coefficient A1, for example, A2 = A1 / 2. Further, when the detection signal S3 is input, the detection signal S1 is input at the same time, but the correction coefficient A1 is masked and the correction coefficient A3 (= 1) is output.

３は第２補正部（色補正部）であり、前記色範囲検出部２の選択回路２４から出力する補正係数Ａ１，Ａ２，Ａ３のいずれかによって、第１補正部１から出力する画質補正済みのカラー画素データＲ，Ｇ，Ｂに対して、乗算して色補正を行う。このとき、補正係数Ａ３が出力したときは、Ａ３＝１であるので、実際は乗算をしない。   Reference numeral 3 denotes a second correction unit (color correction unit), which has been subjected to image quality correction output from the first correction unit 1 by any one of the correction coefficients A1, A2 and A3 output from the selection circuit 24 of the color range detection unit 2. The color correction is performed by multiplying the color pixel data R, G, and B. At this time, when the correction coefficient A3 is output, since A3 = 1, no multiplication is actually performed.

ここで、赤味がかった色に対してのみ色補正を加えたいときは、例えば、色範囲として、色範囲検出部２の第１の検出部２１に、
Ｒ[7:2]≠０、Ｇ「7:3]＝Ｂ「7:3]＝０ (２)
を指定する。これは、画素データＲの第３〜第８ビットの内のいずれか１ビット以上が「１」で第１〜第２ビットが任意あり、画素データＧとＢの第４〜第８ビットの全部が「０」で第１〜第３ビットが任意であるときであり、赤味の色範囲を示す。 Here, when it is desired to apply color correction only to a reddish color, for example, the first detection unit 21 of the color range detection unit 2 as a color range,
R [7: 2] ≠ 0, G “7: 3] = B“ 7: 3] = 0 (2)
Is specified. This is because any one or more of the 3rd to 8th bits of the pixel data R is “1”, the 1st to 2nd bits are arbitrary, and all the 4th to 8th bits of the pixel data G and B are all. Is “0” and the first to third bits are optional, indicating a reddish color range.

また、第２の検出部２２に、
Ｒ[7:2]≠０、Ｇ「7:3]＝Ｂ「7:3]＝１ (３)
を指定する。これは、画素データＲの第３〜第８ビットの内のいずれか１ビット以上が「１」で第１〜第２ビットが任意あり、画素データＧとＢの第４ビットが「１」で第５〜第８ビットが「０」で第１〜第３ビットが任意であるときであり、赤味の色範囲に隣接する色範囲を示す。 In addition, the second detection unit 22
R [7: 2] ≠ 0, G “7: 3] = B“ 7: 3] = 1 (3)
Is specified. This is because one or more of the third to eighth bits of the pixel data R is “1”, the first to second bits are arbitrary, and the fourth bit of the pixel data G and B is “1”. This is a case where the fifth to eighth bits are “0” and the first to third bits are arbitrary, and indicates a color range adjacent to the reddish color range.

また、第３の検出部２３に、
Ｒ[7:3]＝Ｇ「7:3]＝Ｂ「7:3] (４)
を指定する。これは、画素データＲ，Ｇ，Ｂの第４〜第８ビットが同一で第１〜第３ビットが任意であるときであり、ほぼ無彩色を示す。これは、前記式(２)に含まれる色範囲でもある。 In addition, in the third detection unit 23,
R [7: 3] = G “7: 3] = B“ 7: 3] (4)
Is specified. This is when the 4th to 8th bits of the pixel data R, G, B are the same and the 1st to 3rd bits are arbitrary, indicating almost achromatic color. This is also the color range included in the equation (2).

以上により、入力するカラー画素データが式(２)を満足するときは、第１検出部２１から検出信号Ｓ１が出力し、選択回路２４から補正係数Ａ１が出力し、第２補正部３において、第１補正部１の出力カラー画素データＲ，Ｇ，Ｂに対して補正係数Ａ１の乗算が行われるので、赤味色が強められあるいは弱められたカラー画素データＲ，Ｇ，Ｂが、その第２補正部３から出力する。   As described above, when the input color pixel data satisfies the expression (2), the detection signal S1 is output from the first detection unit 21, the correction coefficient A1 is output from the selection circuit 24, and the second correction unit 3 Since the output color pixel data R, G, and B of the first correction unit 1 are multiplied by the correction coefficient A1, the color pixel data R, G, and B whose reddish color is strengthened or weakened are the first. 2 Output from the correction unit 3.

また、入力するカラー画素データが式(３)を満足するときは、第２検出部２２から検出信号Ｓ２が出力し、選択回路２４から補正係数Ａ２が出力し、第２補正部３において、第１補正部１の出力カラー画素データＲ，Ｇ，Ｂに対して補正係数Ａ２の乗算が行われるので、式(２)で表される色範囲に隣接する色範囲の色が若干補正される。この補正は、検出信号Ｓ１が入力したときに赤味色が強められるときはそれより若干少なく強められ、弱められるときはそれより若干少なく弱められ、これによって、式(２)で表される色範囲の補正後の色と他の色との色段差が緩和される。   When the input color pixel data satisfies the expression (3), the detection signal S2 is output from the second detection unit 22, the correction coefficient A2 is output from the selection circuit 24, and the second correction unit 3 Since the output color pixel data R, G, and B of the 1 correction unit 1 are multiplied by the correction coefficient A2, the color in the color range adjacent to the color range represented by the equation (2) is slightly corrected. When the detection signal S1 is input, this correction is slightly weaker when the reddish color is strengthened, and slightly weaker when it is weakened. Thus, the color represented by the equation (2) is obtained. The color difference between the color after the correction of the range and the other color is reduced.

さらに、入力カラー画素データが式(４)を満足するとき、つまり無彩色又はこれに近い色のときは、第３検出部２３から検出信号Ｓ３が出力する。従って、第１検出部２１から検出信号Ｓ１が出力したとしても、選択回路２４からは補正係数Ａ３が出力し、このときは第１補正部１の出力カラー画素データＲ，Ｇ，Ｂに対して乗算は行われない。よって、無彩色又はこれに近い色が着色されることが防止される。   Further, when the input color pixel data satisfies the expression (4), that is, when the input color pixel data is an achromatic color or a color close thereto, a detection signal S3 is output from the third detection unit 23. Therefore, even if the detection signal S1 is output from the first detection unit 21, the selection circuit 24 outputs the correction coefficient A3. At this time, the output color pixel data R, G, B of the first correction unit 1 is output. No multiplication is performed. Therefore, it is prevented that an achromatic color or a color close thereto is colored.

なお、以上では、色範囲検出部２が、第１補正部１への入力カラー画素データＲ，Ｇ，Ｂの色範囲を検出していたが、第１補正部１から出力するカラー画素データＲ，Ｇ，Ｂの色範囲を検出しても良い。   In the above description, the color range detection unit 2 detects the color range of the input color pixel data R, G, and B to the first correction unit 1, but the color pixel data R output from the first correction unit 1. , G, B color ranges may be detected.

また、補正係数Ａ１，Ａ２は、全部のカラー画素データＲ，Ｇ，Ｂに共通としたが、互いに異ならせても良いことは勿論である。この場合は、色変換の意味合いが強くなる。   The correction coefficients A1 and A2 are common to all the color pixel data R, G, and B, but may be different from each other. In this case, the meaning of color conversion becomes strong.

また、補正係数Ａ１，Ａ２，Ａ３は、第２補正部３に検出信号Ｓ１，Ｓ２，Ｓ３を入力させ、ここで生成して乗算を行うようにしても良い。   Further, the correction coefficients A1, A2, and A3 may be generated by causing the second correction unit 3 to input the detection signals S1, S2, and S3 and multiplying them.

また、以上では、第２補正部３が補正係数Ａ１，Ａ２をカラー画素データＲ，Ｇ，Ｂに対して乗算することにより色補正を行う場合について説明したが、ある補正値をカラー画素データＲ，Ｇ，Ｂに共通にあるいは異ならせて加算あるいは減算してもよい。   In the above description, the second correction unit 3 performs color correction by multiplying the color pixel data R, G, and B by the correction coefficients A1, A2, but a certain correction value is set to the color pixel data R. , G, B may be added or subtracted in common or differently.

本発明の実施例のカラー画像補正装置のブロック図である。1 is a block diagram of a color image correction apparatus according to an embodiment of the present invention. 本発明の背景としたカラー画像補正装置のブロック図である。1 is a block diagram of a color image correction apparatus as a background of the present invention.

符号の説明Explanation of symbols

１：第１補正部（画質補正部）
２，２Ａ：色範囲検出部、２１：第１検出部、２２：第２検出部、２３：第３検出部、２４：選択部
３，３Ａ：第２補正部（色補正部） 1: First correction unit (image quality correction unit)
2, 2A: Color range detection unit, 21: First detection unit, 22: Second detection unit, 23: Third detection unit, 24: Selection unit 3, 3A: Second correction unit (color correction unit)

Claims (4)

入力するカラー画素データの画質補正を行い、該画質補正の前又は後のカラー画素データで決まる色が特定の色範囲にあるとき、前記画質補正済みのカラー画素データを再補正して色補正を行うカラー画像補正方法であって、
前記画質補正の前又は後のカラー画素データで決まる色が前記特定の色範囲にあるときに、第１の再補正を行い、前記特定の色範囲に隣接する色範囲にあるときに、前記第１の再補正に比較して補正効果が小さい第２の再補正を行うことを特徴とするカラー画像補正方法。 The image quality of the input color pixel data is corrected, and when the color determined by the color pixel data before or after the image quality correction is in a specific color range, the color pixel data after the image quality correction is corrected again to perform color correction. A color image correction method to be performed,
When the color determined by the color pixel data before or after the image quality correction is in the specific color range, a first re-correction is performed, and when the color is in a color range adjacent to the specific color range, the first 2. A color image correction method, wherein a second re-correction is performed that has a smaller correction effect than the first re-correction. 入力するカラー画素データの画質補正を行い、該画質補正の前又は後のカラー画素データで決まる色が特定の色範囲にあるとき、前記画質補正済みのカラー画素データを再度補正して色補正を行うカラー画像補正方法であって、
前記画質補正の前又は後の前記カラー画素データで決まる色が無彩色又はこれに近い色範囲であるときは、前記特定の色範囲にあるときであっても、前記再補正を行わないことを特徴とするカラー画像補正方法。 The image quality of the input color pixel data is corrected, and when the color determined by the color pixel data before or after the image quality correction is in a specific color range, the color pixel data after the image quality correction is corrected again to perform color correction. A color image correction method to be performed,
When the color determined by the color pixel data before or after the image quality correction is an achromatic color or a color range close thereto, the recorrection is not performed even when the color is in the specific color range. A characteristic color image correction method. 入力するカラー画素データの画質補正を行う第１補正部と、該第１補正部の入力側又は出力側のカラー画素データを入力して該カラー画素データで決まる色が特定の色範囲に含まれるとき第１の検出信号を出力する色範囲検出部と、該色範囲検出部が前記第１の検出信号を出力したとき前記第１補正部から出力するカラー画素データを補正する第２補正部とを備えるカラー画像補正装置であって、
前記色範囲検出部は、さらに、前記第１補正部の入力側又は出力側のカラー画素データで決まる色が前記特定の色範囲に隣接するとき第２の検出信号を出力し、
前記第２補正部は、前記色範囲検出部が前記第１の検出信号を出力したときに、前記第１補正部から出力するカラー画素データに第１の再補正を行い、前記色範囲検出部が前記第２の検出信号を出力したとき、前記第１の再補正よりも補正効果の小さい第２の再補正を行うことを特徴とするカラー画像補正装置。 A specific color range includes a first correction unit that performs image quality correction of input color pixel data and a color determined by the color pixel data by inputting color pixel data on the input side or output side of the first correction unit. A color range detection unit that outputs a first detection signal, and a second correction unit that corrects color pixel data output from the first correction unit when the color range detection unit outputs the first detection signal; A color image correction apparatus comprising:
The color range detection unit further outputs a second detection signal when a color determined by color pixel data on the input side or output side of the first correction unit is adjacent to the specific color range,
The second correction unit performs first re-correction on the color pixel data output from the first correction unit when the color range detection unit outputs the first detection signal, and the color range detection unit When the second detection signal is output, the second re-correction having a correction effect smaller than that of the first re-correction is performed. 入力するカラー画素データの画質補正を行う第１補正部と、該第１補正部の入力側又は出力側のカラー画素データを入力して該カラー画素データで決まる色が特定の色範囲に含まれるとき第１の検出信号を出力する色範囲検出部と、該色範囲検出部が前記第１の検出信号を出力したとき前記第１補正部から出力するカラー画素データを補正する第２補正部とを備えるカラー画像補正装置であって、
前記色範囲検出部は、さらに、前記第１補正部の入力側又は出力側のカラー画素データで決まる色が無彩色又はこれに近い色範囲に含まれるとき、第３の検出信号を出力し、
前記第２補正部は、前記色範囲検出部が前記第１の検出信号を出力したときであっても、前記色範囲検出部が前記第３の検出信号を出力したときには、前記第２補正部による再補正を行わないことを特徴とするカラー画像補正装置。 A specific color range includes a first correction unit that performs image quality correction of input color pixel data and a color determined by the color pixel data by inputting color pixel data on the input side or output side of the first correction unit. A color range detection unit that outputs a first detection signal, and a second correction unit that corrects color pixel data output from the first correction unit when the color range detection unit outputs the first detection signal; A color image correction apparatus comprising:
The color range detection unit further outputs a third detection signal when a color determined by the color pixel data on the input side or output side of the first correction unit is included in an achromatic color or a color range close thereto.
Even when the color gamut detection unit outputs the first detection signal, the second correction unit performs the second correction unit when the color gamut detection unit outputs the third detection signal. A color image correction apparatus characterized by not performing re-correction according to the above.
JP2006338401A 2006-12-15 2006-12-15 Method and device for correcting color image Withdrawn JP2008153846A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2006338401A JP2008153846A (en) 2006-12-15 2006-12-15 Method and device for correcting color image

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2006338401A JP2008153846A (en) 2006-12-15 2006-12-15 Method and device for correcting color image

Publications (1)

Publication Number Publication Date
JP2008153846A true JP2008153846A (en) 2008-07-03

Family

ID=39655586

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2006338401A Withdrawn JP2008153846A (en) 2006-12-15 2006-12-15 Method and device for correcting color image

Country Status (1)

Country Link
JP (1) JP2008153846A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20230308774A1 (en) * 2022-03-25 2023-09-28 Samsung Electronics Co., Ltd. Image processing method and electronic device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20230308774A1 (en) * 2022-03-25 2023-09-28 Samsung Electronics Co., Ltd. Image processing method and electronic device

Similar Documents

Publication Publication Date Title
KR101990956B1 (en) Device for converting color gamut and method thereof
US20080259216A1 (en) Color signal converting apparatus, video display apparatus including the same, and color signal converting method
JP5178473B2 (en) Image processing apparatus and image processing method
KR101927968B1 (en) METHOD AND DEVICE FOR DISPLAYING IMAGE BASED ON METADATA, AND RECORDING MEDIUM THEREFOR
JP2008541598A (en) Method and apparatus for color conversion brightness correction
EP2391113B1 (en) Image processing method, image processing device and recording medium
JP2006243454A (en) Image display device
JP2005295405A (en) Color converting method and image processing apparatus
JPWO2010067488A1 (en) Color correction apparatus and color correction method
JP2007017862A (en) Image display device
US20090051817A1 (en) Method and device for image sharpness adjustment
JP2007019970A (en) Device and method for color correction
JP2008153846A (en) Method and device for correcting color image
JP2007259434A (en) Image processing apparatus and method of the same
JP2008042711A (en) Color converter, color converting method, color conversion program, color conversion coefficient creating apparatus, color conversion coefficient creating method, and color conversion coefficient creation program
JP2006128986A (en) Image processing apparatus
JP4461164B2 (en) Color conversion apparatus and color conversion method
JP4853296B2 (en) Color conversion apparatus, color conversion method, color conversion program, color conversion coefficient creation apparatus, color conversion coefficient creation method, and color conversion coefficient creation program
JP2006229616A (en) Circuit for processing video signals
JP2007019684A (en) Color image correction method and device
JP2008098814A (en) Video-signal processor
JP4069860B2 (en) Color conversion apparatus and color conversion method
JP2008067343A (en) Color correction circuit, drive device, and display device
JP4773739B2 (en) Image processing method
JP2008245274A (en) Method and apparatus for regulating color conversion profile

Legal Events

Date Code Title Description
A300 Withdrawal of application because of no request for examination

Free format text: JAPANESE INTERMEDIATE CODE: A300

Effective date: 20100302