JPS62213383A - Gradation expression image reducing and enlarging device of pseudo half tone system - Google Patents
Gradation expression image reducing and enlarging device of pseudo half tone systemInfo
- Publication number
- JPS62213383A JPS62213383A JP61055792A JP5579286A JPS62213383A JP S62213383 A JPS62213383 A JP S62213383A JP 61055792 A JP61055792 A JP 61055792A JP 5579286 A JP5579286 A JP 5579286A JP S62213383 A JPS62213383 A JP S62213383A
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- image
- reduction
- enlargement
- average density
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- 238000000034 method Methods 0.000 claims description 9
- 238000001739 density measurement Methods 0.000 claims description 6
- 238000005259 measurement Methods 0.000 claims description 4
- 238000012937 correction Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 4
- 239000011159 matrix material Substances 0.000 description 4
- 238000007796 conventional method Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 239000003550 marker Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
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Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、画像の階調表現を疑似中間調方式で行う装置
に関する。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an apparatus that expresses the gradation of an image using a pseudo-halftone method.
従来の技術
画像を扱う装置で階調表現をおこなう方法の一つに疑似
中間調方式を用いたものがある。これは。2. Description of the Related Art One of the methods for expressing gradation in a conventional image processing device is to use a pseudo halftone method. this is.
送ろうとする画を一定の領域毎に区切り、各部分の平均
の濃度が元の画の対応する領域の平均濃度と等しくなる
ように白と黒の画像を配置した画をつ（す、それを相手
機におくって疑似的に階調表現を行う方法である。Divide the image to be sent into certain areas, and create an image with white and black images arranged so that the average density of each area is equal to the average density of the corresponding area of the original image. This is a method of performing pseudo gradation expression by sending it to the other party's machine.
発明が解決しようとする問題点
しかしながら、上述した従来の画像を扱う装置では、疑
似中間調方式の階調表現で一担画素を配置した画を縮小
率または拡大率に従って画素を間引きしたり付加したり
することによって縮小又は拡大すると、得られた画の濃
度が、間引き又は付加をおこなった画素の近辺で元の画
の濃度と異な本発明は従来の上記事情に鑑みてなされた
ものであり、従って本発明の目的は、従来の技術に内在
する上記欠点を解消することを可能とした階調表現画像
の新規な縮小拡大装置を提供することにある。Problems to be Solved by the Invention However, in the above-mentioned conventional image handling devices, pixels are thinned out or added according to the reduction rate or enlargement rate of an image in which one-color pixels are arranged using the pseudo halftone method. The present invention, in which the density of the obtained image differs from the density of the original image in the vicinity of the thinned out or added pixels when the image is reduced or enlarged by SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a novel reduction/enlargement apparatus for gradation-expressing images, which makes it possible to eliminate the above-mentioned drawbacks inherent in the conventional techniques.
問題点を解決するための手段
上記目的を達成すめ為に、本発明に係る階調表現画像の
縮小拡大装置は、縮小または拡大を行う前の画における
ある領域の平均濃度を求める第１の平均濃度計測部と、
縮小率または拡大率に従って画素を間引きしめたり付加
したりする縮小拡大部と縮小または拡大を行う前に平均
濃度を求めた領域の縮小または拡大を行った後の平均濃
度を求める第２の平均濃度計測部と、これら第１及び第
２の二つの平均濃度計測部の計測結果を比較する濃度比
較部と、この濃度比較部の比較結果に従って縮小または
拡大を行った後の画の画素の一部を白又は黒に置き換え
るように指示する画素置き換え制御部と、この画素置換
え制御部の指示に従って縮小または拡大を行った後の画
の画素の一部を白又は黒に置き換える画素置き換え部と
を備えて構成される。Means for Solving the Problems In order to achieve the above object, the gradation expression image reduction/enlargement apparatus according to the present invention uses a first average method to obtain the average density of a certain area in an image before reduction or enlargement. A concentration measurement section,
A reduction/enlargement section that thins out or adds pixels according to the reduction or enlargement ratio, and a second average density that obtains the average density after reducing or enlarging the area whose average density was obtained before reduction or enlargement. a measuring section, a density comparing section that compares the measurement results of the first and second average density measuring sections, and a part of the pixels of the image after reduction or enlargement according to the comparison results of the density comparing section. A pixel replacement control unit that instructs to replace the pixel with white or black, and a pixel replacement unit that replaces some of the pixels of the image after reduction or expansion with white or black according to instructions from the pixel replacement control unit. It consists of
実施例
以下に、本発明をその好ましい一実施例について図面を
参照して詳細に説明する。EXAMPLE Hereinafter, a preferred embodiment of the present invention will be explained in detail with reference to the drawings.
第１図は本発明の一実施例を示すブロック構成図である
。第１図を参照するに、本発明の一実施例は、縮小また
は拡大を行う前の画におけるある領域の平均濃度を求め
る平均濃度計測部１と、縮小率または拡大率に従って画
素を間引きしめたり付加したりする縮小拡大部２と、縮
小または拡大を行う前に平均濃度を求めた領域の縮小ま
たは拡大を行った後の平均濃度を求める平均濃度計測部
３と、平均濃度計測部１と平均濃度計測部３の計測結果
を比較する濃度比較部４と、濃度比較部４の比較結果に
従って縮小または拡大を行った後の画の画素の一部を白
又は黒に置き換えるようにｔ旨示する画素置き換え制御
部５と、画素置き換え制御Ｗ５５の指示に従って縮小ま
たは拡大を行った後の画の画素の一部を白又は黒に置き
換える画素置き換え部６とで構成される。FIG. 1 is a block diagram showing one embodiment of the present invention. Referring to FIG. 1, one embodiment of the present invention includes an average density measuring section 1 that calculates the average density of a certain area in an image before reduction or enlargement, and thinning out pixels according to the reduction or enlargement ratio. an average density measurement unit 3 that calculates the average density after reducing or enlarging the area whose average density was calculated before reduction or expansion; The density comparison unit 4 compares the measurement results of the density measurement unit 3 and indicates t to replace some of the pixels of the image after reduction or expansion with white or black according to the comparison result of the density comparison unit 4. It is composed of a pixel replacement control section 5 and a pixel replacement section 6 that replaces some of the pixels of an image after reduction or enlargement with white or black according to instructions from a pixel replacement control W55.
一例として、第２図に示す４Ｘ４のＢａｙｅ ｒ型マト
リクスで階調表現された疑似中間調の画を考える。ある
領域Ｐが、第３図の様にＢａｙｅ ｒ型マトリクスの閾
値５以上の濃度であったとする。As an example, consider a pseudo-halftone image expressed in gradations using a 4×4 Bayer r-type matrix shown in FIG. Assume that a certain region P has a density that is equal to or higher than the threshold value 5 of the Bayer r-type matrix, as shown in FIG.
平均濃度計測部１は、疑似中間調方式で階調表現された
画の画信号７を受は取り、その画のある領域Ｐの平均濃
度をもとめ、その結果を領域Ｐの平均濃度８として濃度
比較部４に送る。The average density measurement unit 1 receives an image signal 7 of an image expressed in gradation using the pseudo-halftone method, determines the average density of an area P in the image, and uses the result as the average density 8 of the area P. Send it to comparison section 4.
このとき、本例ではこの領域Ｐの平均濃度ＫＴは、全黒
の場合を１、全白の場合をＯとすると１つ
である。At this time, in this example, the average density KT of this area P is 1 when it is all black and O is when it is all white.
縮小拡大！２は画信号７をうけ取り、縮小率または拡大
率に従って画素を間引きしめたり付加したりして画の縮
小または拡大を行い、その結果を縮小または拡大の結果
の画の画信号８として出力ここで縮小拡大部２は、第４
図の様な間引きのパターンで画素を間引いて画の縮小を
行うとする平均濃度計測部３は、縮小または拡大を行っ
た後の画の画信号９の平均濃度を求める。求められた平
均濃度は、縮小または、拡大を行った後の画の平均濃度
ＩＯとして、濃度比較部４に出力される。Shrink and expand! 2 receives the image signal 7, reduces or enlarges the image by thinning out or adding pixels according to the reduction or enlargement ratio, and outputs the result as the image signal 8 of the image as a result of reduction or enlargement. The reduction/enlargement section 2
The average density measurement unit 3, which reduces the image by thinning out pixels in a thinning pattern as shown in the figure, calculates the average density of the image signal 9 of the image after reduction or enlargement. The obtained average density is output to the density comparison section 4 as the average density IO of the image after reduction or enlargement.
このとき、第５図のように、領域Ｐの縮小後の平均濃度
ＫＲＴは
である。At this time, as shown in FIG. 5, the average density KRT of the area P after reduction is .
濃度比較部４は、縮小または拡大を行う前の画の平均瀾
・度８と縮小または拡大を行った後の画の平均濃度ｌＯ
とを比較し、その結果を濃度比較結果信号１１として、
画素置き換え制御部５に送る。The density comparison unit 4 compares the average density of the image before reduction or enlargement, 8, and the average density of the image after reduction or enlargement, lO.
and use the result as the density comparison result signal 11,
It is sent to the pixel replacement control section 5.
画素置き換え制御部５は、縮小または拡大を行う前の画
の平均濃度８と、縮小または拡大を行った後の画の平均
濃度ＩＯとができるだけ近接するよろにどれｆＩけの百
！を白マは毘を二宥缶漁ｉス六１か画素置き換え制御信
号１２として画素置き換え部６に送る。この例では、領
域Ｐの縮小後の画の画素のうち２ドツトを白画素から黒
画素に置き換える画素置き換え部６は、画素置き換え制
御信号１２の指示に従って領域Ｐの縮小または拡大の結
果の画の画信号９の画素を白又は黒に置き換え、濃度補
正後の縮小画の画信号１３として出力する。この例では
、画素置き換え部８によって、第６図のように画の画素
の一部を置き換えられた濃度補正後の画の平均濃度Ｋｃ
は
となり、（２）式の０．５８に比べ（１）式の０．７５
により近い平均濃度となる。The pixel replacement control unit 5 is configured to make the average density 8 of the image before reduction or enlargement as close as possible to the average density IO of the image after reduction or enlargement. The white marker sends the pixel to the pixel replacement section 6 as a pixel replacement control signal 12. In this example, the pixel replacement unit 6 replaces two dots of the pixels of the reduced image in the region P from white pixels to black pixels, according to instructions from the pixel replacement control signal 12, and the pixel replacement unit 6 replaces the pixels of the reduced or enlarged image of the region P according to instructions from the pixel replacement control signal 12. The pixels of the image signal 9 are replaced with white or black, and the image signal 13 of the reduced image after density correction is output. In this example, the average density Kc of the image after density correction in which some of the pixels of the image are replaced by the pixel replacement unit 8 as shown in FIG.
is 0.75 in equation (1) compared to 0.58 in equation (2).
This results in a closer average concentration.
発明の詳細
な説明したように、本発明によれば、縮小または拡大を
行う前の画におけるある領域の平均濃度と、縮小率また
は拡大率に従って画素を間引きしたり付加したりして縮
小または拡大を行った後の画の平均濃度とを比較し、そ
の比較結果に従って、縮小または拡大を行った後の画の
画素の一部を白又は黒に置き換えるように補正すること
によって、得られた画の濃度が間引き又は付加をおこな
った画素の近辺で元の画の濃度と異なることが少なく画
質の劣化が少なくなり、疑似中間調方式で階調表現を行
なった画の縮小または拡大が可能となる。As described in detail, according to the present invention, reduction or expansion is performed by thinning out or adding pixels according to the average density of a certain area in an image before reduction or expansion, and the reduction or expansion rate. The image obtained by comparing the average density of the image after performing the reduction or enlargement and correcting it by replacing some of the pixels of the image after reduction or enlargement with white or black according to the comparison result. The density of the pixels near the thinned out or added pixels is less likely to differ from the density of the original image, resulting in less deterioration of image quality, and it is possible to reduce or enlarge an image whose gradation is expressed using the pseudo-halftone method. .
第１図は本発明の一実施例を示すブロック構成図、第２
図はＢａｙｅ ｒ型のマ）リクスの閾値を示す図、第３
図はＢａｙｅ ｒ型マトリクスの閾値５以上の濃度の領
域Ｐの一例を示す図、第４図は間引きの一例を示す図、
第５図は間引かれた領域Ｐの一例を示す図、第８図は間
引かれた領域Ｐの補正後の一例を示す図である。
１００．平均濃度計測部、２．、、縮小拡大部３３０．
平均濃度計測部、４．、、濃度比較部、５００９画素置
き換え制御部、８．、、画素置き換え部、７１０８画信
号１Ｓ１０．領域Ｐの平均濃度、９．、、縮小または拡
大の結果の画の画信号、１０． 、 、縮小または拡大
を行った後の画の平均濃度、Ｉｌ、 、 、 ／Ｊｕ濃
度比較結果信号、１２． 、 、画素置きかえ制御信号
、１３． 、 、濃度補正後の縮小画の画信号
特許出願人、 日本電気株式会社
代 理 人 弁理士熊谷雄太部
第１１１１１
第２図 第３図
（数値は閾ｆｌｕ） ・：黒画素０：白
画素
第５図 第６図
補正前 補正後
第４図
×：間引き画素FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG.
The figure shows the threshold of the Bayer r-type matrix.
The figure shows an example of a region P of a Bayer r-type matrix with a concentration of 5 or more, and FIG. 4 shows an example of thinning.
FIG. 5 is a diagram showing an example of the thinned out area P, and FIG. 8 is a diagram showing an example of the thinned out area P after correction. 100. average concentration measuring section, 2. ,, reduction/enlargement section 330 .
average concentration measuring section, 4. , , density comparison section, 5009 pixel replacement control section, 8. , , pixel replacement unit, 7108 pixel signal 1S10. Average density of area P, 9. , , the image signal of the image as a result of reduction or enlargement; 10. , , average density of the image after reduction or enlargement, Il, , , /Ju density comparison result signal, 12. , , pixel replacement control signal, 13. , , Image signal of reduced image after density correction Patent applicant: NEC Co., Ltd. Attorney Yutabe Kumagai No. 11111 Figure 2 Figure 3 (Numbers are threshold flu) ・: Black pixel 0: White pixel No. Figure 5 Figure 6 Before correction Figure 4 After correction ×: Thinned pixels
Claims (1)
度を求める第１の平均濃度計測部と、縮小率または拡大
率に従って画素を間引きしたり付加したりする縮小拡大
部と、縮小または拡大を行う前に平均濃度を求めた領域
の縮小または拡大を行った後の平均濃度を求める第２の
平均濃度計測部と、前記第１及び第２の平均濃度計測部
の計測結果を比較する濃度比較部と、該濃度比較部の比
較結果に従って縮小または拡大を行った後の画の画素の
一部を白又は黒に置き換えるように指示する画素置き換
え制御部と、該画素置き換え制御部の指示に従って縮小
または拡大を行った後の画の画素の一部を白又は黒に置
き換える画素置き換え部とを備えることを特徴とする疑
似中間調方式による階調表現画像の縮小拡大装置。A first average density measuring section that calculates the average density of a certain area in an image before performing reduction or enlargement; a reduction/enlargement section that thins out or adds pixels according to the reduction or enlargement ratio; and a reduction or enlargement section that performs reduction or enlargement. a second average density measurement unit that calculates the average density after reducing or expanding the area for which the average density was previously calculated; and a density comparison unit that compares the measurement results of the first and second average density measurement units. a pixel replacement control section that instructs to replace some of the pixels of the image after reduction or enlargement with white or black according to the comparison result of the density comparison section; 1. An apparatus for reducing and enlarging a gradation expression image using a pseudo halftone method, comprising: a pixel replacement unit that replaces some of the pixels of an image after enlarging with white or black.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61055792A JPS62213383A (en) | 1986-03-13 | 1986-03-13 | Gradation expression image reducing and enlarging device of pseudo half tone system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61055792A JPS62213383A (en) | 1986-03-13 | 1986-03-13 | Gradation expression image reducing and enlarging device of pseudo half tone system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS62213383A true JPS62213383A (en) | 1987-09-19 |
Family
ID=13008760
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61055792A Pending JPS62213383A (en) | 1986-03-13 | 1986-03-13 | Gradation expression image reducing and enlarging device of pseudo half tone system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62213383A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8606048B2 (en) | 2010-09-24 | 2013-12-10 | Konica Minolta Business Technologies, Inc. | Image processing apparatus and image processing method |
-
1986
- 1986-03-13 JP JP61055792A patent/JPS62213383A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8606048B2 (en) | 2010-09-24 | 2013-12-10 | Konica Minolta Business Technologies, Inc. | Image processing apparatus and image processing method |
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