JPH0514689A - Picture editer - Google Patents

Abstract

PURPOSE:To obtain a sharp edit picture by preventing mis-erasure of a marker and preventing a picture part from being thinned with respect to the picture editer used for a digital copying machine. CONSTITUTION:This editer is provided with a specific color picture detection means 213 detecting a picture part Yc of a specific color in entered picture information, an area discrimination means outputting a picture presence signal Yo discriminating a background area with a low density from a picture area with a high density in the picture information and density conversion means 205,215 converting the density of the background area in the part adjacent to the specific color picture part and the relevant picture part into a prescribed density.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image editing apparatus used in a digital copying machine or the like.

[0002]

2. Description of the Related Art In a digital copying machine or the like, it is possible to perform partial negative / positive inversion, hollowing, trimming, masking and other image editing on image data read from an original.

As a method of designating an editing area in such image editing, there is a method of inputting the coordinate position on the document surface with a tablet or a key. However, in the coordinate position designation method, the position accuracy of the designated area is poor, and in many cases, only the rectangular edit area surrounded by the designated points can be designated, so it is difficult to designate the edit area having a complicated shape.

To address this problem, a marker pen of a color different from that of the original image is used, and the edit area is designated by enclosing or filling the edit area with the marker pen, and a marker signal is detected from the marker and detected. Various devices have been proposed that detect an editing area designated based on a marker signal in real time.

For example, in Japanese Unexamined Patent Publication No. 63-279661, an original image is read by scanning an original with an image sensor in the main scanning direction and the sub-scanning direction, and a marker is selected from the image data obtained by the scanning. There is shown a device that detects a pixel determined to be a color corresponding to a specific color of a pen as a marker signal and detects an editing area based on the marker signal.

As described above, in the case of the method of designating the editing area by the marker, it is necessary to erase the marker from the image information and restore the original natural image after detecting the editing area. The marker is erased by converting the marker portion of the image data into white data.

[0007]

In that case, conventionally, in order to ensure the erasure of the marker and prevent erroneous erasure, a portion thicker (wider) than the width of the detected marker portion is erased from the image data. It has become.

Therefore, especially when the marker is overlapped with the image portion by specifying the area by filling, the marker portion for erasing and the image portion are continuously adjacent to each other, so that the width of the marker portion is wide. There is a problem that the image portion becomes thinner by that amount by erasing thicker than that.

For example, when the image portion is a character,
The edge portion of the character is shaved and thinned, so that a so-called thinning phenomenon of the character occurs, so that the sharpness or quality of the copied image is deteriorated.

The present invention has been made in view of the above problems, and an object thereof is to prevent erroneous deletion of a marker and to prevent the image portion from becoming thin so as to obtain a clear edited image.

[0011]

In order to solve the above-mentioned problems, an apparatus according to the invention of claim 1 is a specific color image detecting means for detecting an image portion of a specific color in input image information, Of the image information, an area discrimination unit that discriminates a background area having a low density and an image area having a high density, and an area discrimination unit that distinguishes between the image portion of the specific color and a portion adjacent to the image portion. A density conversion unit that converts the density of the portion determined to be the area to a predetermined density is configured.

[0012]

The specific color image detecting means detects an image portion such as a marker having a specific color in the input image information. The density converting means converts the image portion of the specific color into a predetermined density, and at that time, not only the image portion of the specific color but also the area determining means of the area adjacent to the image portion determines the background area. As for the part that was
Convert to a predetermined density.

[0013]

FIG. 2 is a sectional front view showing a schematic structure of a copying machine 1 having a thickening processing section 223 according to the present invention.

The copying machine 1 outputs an image reader section IR which outputs image information obtained by scanning an original image as an image signal S1 and a single-color or two-color copied image based on the image signal S1 by electrophotography. It is composed of a laser printer unit LP for forming an image.

In the image reader section IR, the optical system 1
Reference numeral 0 is composed of a scanner 11 which can reciprocate below a document table glass 18, mirrors 13 and 14, a main lens 15, a full-color image sensor 16 and the like. The scanner 11 has an exposure lamp 12 that irradiates a document, and is driven by a motor 17 to scan a document placed on a document table glass 18.

The image of the original document is read by the image sensor 16 as color signals of three primary colors of additive colors R (red), G (green), and B (blue). The photoelectric conversion signal S0 output from the image sensor 16 is quantized by the signal processing unit 20, subjected to various signal processes depending on the copy mode, and then sent to the laser printer unit LP as an image signal S1.

The laser printer section LP includes a laser optical system 30 having a semiconductor laser (not shown) as a light source and a photosensitive drum 4.
And an image forming system 40 for carrying out an electrophotographic process.

The laser optical system 30 comprises a polygon mirror 3
1, the Fθ lens 32, the reflection mirror 37, and the like, and emits the laser light controlled by the control unit 50 based on the image signal S1 to expose the photosensitive drum 41.

In the image forming system 40, a charging charger 43 and a developing device 44 for forming a first color image and a charging charger 4 for forming a second color image are formed around the photosensitive drum 41.
5, a developing device 46, a transfer charger 47, a separation charger 48, a cleaner 49, and the like.

A latent image corresponding to the original image is formed on the surface of the photosensitive drum 41 charged by the charging chargers 43 and 45 by the above-mentioned exposure. The latent image is developed as a toner image by one or both of the developing devices 44 and 46. The toner image is transferred to the paper fed from the paper cassette 81 or 82.

Although the developing color of the developing devices 44 and 46 can be arbitrarily selected by exchanging the toner, the developing color of the developing device 44 is black, for example, and the developing device 4 is used here.
The development color of No. 6 is assumed to be red, for example.

The edit / copy function of the copying machine 1 will now be described. In the normal copy mode, a black monocolor image is formed using only the developing device 44 regardless of the color of the original. On the other hand, in the edit / copy mode, the designated color portion in the original image in the color edit mode, and the marker area designated by the marker in the marker edit mode are copied or deleted in red by using the developing device 46. Edit. As the designated color at this time, "red" in the copying machine 1,
It is possible to select three colors of "blue" and "red or blue".

The operation panel (not shown) is provided with operation keys corresponding to the designated colors "red" and "blue", and if any one of them is pressed, the designated color becomes "red" or "blue". Become. If both are pressed, the designated color becomes "red or blue". For example, when the operator designates "red or blue" as a designated color in editing and copying, the red part and the blue part in the original image are copied in red, and the other parts are copied in black.

In order to realize such editing and copying, in the image reader section IR, the signal processing section 2 will be described later.
Within 0, the color of each pixel of the original image is discriminated (color discrimination).
Then, the color discrimination data Yc obtained as a result of the discrimination,
Alternatively, the marker area signal EE detected based on the color discrimination data Yc is output to the laser printer section LP as the editing signal S2 in synchronization with the image information (image signal S1).

In the edit / copy mode, the laser printer section LP uses the edit signal S2 to perform the above-described two operations.
It is possible to form color images.

FIG. 3 is a plan view of the image sensor 16.

The image sensor 16 includes three CCD arrays 16R, 16G, 1 extending in the main scanning direction of document scanning.
It is a one-chip solid-state imaging device in which 6B is integrated.

Each CCD array 16R, 16G, 16B
Has a CCD element corresponding to 5000 pixels, respectively, and can read an A3 size document at a resolution of 16 lines / mm. CCD array 16R, 16G, 16
The light receiving surface of B is provided with a spectral filter that transmits R, G, and B lights, respectively, in order to separate and read the original image into three primary colors.

Further, in the image sensor 16, the CCD
The arrays 16R, 16G, and 16B are arranged in parallel with each other with a pitch of 12 pixels (that is, 12 lines) in the sub-scanning direction. Therefore, for the same pixel,
The output timing of the photoelectric conversion signal by the CCD array 16G is delayed from the output timing of the CCD array 16R by a fixed time (12 lines of sub-scanning time), and the output timing of the CCD array 16B is the CCD array 1
It is delayed by the same time as the output timing of 6G.

That is, the information of each color read by separating the pixels into three colors is output in the order of R, G, B with a fixed time delay. Since the sub-scanning speed is changed according to the copy magnification, the deviation of the output timing of each color also increases or decreases according to the copy magnification.

FIG. 4 is a block diagram showing the configuration of the signal processing section 20.

R output from the image sensor 16,
The photoelectric conversion signals S0 of G and B colors are input to the AD conversion unit 202. In the AD conversion unit 202, the inputted photoelectric conversion signal S0 is subjected to signal processing such as waveform shaping, signal amplification and dark current removal, and then is quantized to be an 8-bit (256 gradation) digital signal. Convert to.

The shading correction unit 203 adds shading correction to the digital signal from the AD conversion unit 202 and outputs it as image data DR, DG, DB.

Of the image data DR, DG, and DB, the green image data DG is extracted as image information obtained by reading the original image, and is input to the density correction unit 204. G
(Green) is a color in the wavelength region having the highest relative luminous efficiency among R, G, and B. That is, the light and shade of the original image is recognized by the naked eye mainly by the light intensity of G. Therefore, by using the green image data DG as it is as the image density information, it is possible to obtain a copied image which is comparable in terms of image quality, and the subsequent processing circuit configuration is simplified.

The density correction unit 204 performs gamma correction on the image data DG so as to correctly reproduce the density of the original image. A delay memory for delaying the image data DG to match the transmission timing with the color discrimination data Yc or the marker area signal EE is provided in the preceding stage of the density correction unit 204.

The next image editing unit 205 is an editing mode signal md set by the CPU 201, and an editing area discrimination unit 21.
5, the marker signal Ym output from the switch 5, or the switching unit 21.
In accordance with the color discrimination data Yc or the marker area signal EE output from 6 and the like, the image data DG is subjected to editing processing such as marker erasing, negative / positive inversion, hollowing, halftone, halftone, trimming and masking. ..

The scaling processor 206 electrically scales the image data DG by overlapping pixels or thinning pixels according to the copy magnification. The color discrimination data Yc and the like are also input to the scaling processing unit 206 in synchronization with the image data DG, and these are also scaled together with the image data DG.

The image data DG output from the scaling processing unit 206 is subjected to processing such as edge enhancement and smoothing for improving image quality by the filter unit 207.

The image data DG, the color discrimination data Yc, etc. are output to the laser printer section L as an image signal S1 and an editing signal S2 via the output interface 208.
It is output to P.

The output form of the image signal S1 may be an 8-bit digital signal indicating the image density as it is, or may be bit data binarized by a dither method or the like. It can also be an analog signal.

On the other hand, the image data DR, DG, DB are input to the selector 211 for color discrimination. Selector 2
Reference numeral 11 is controlled by the CPU 201 and selects two-color image data from the three-color image data DR, DG, and DB in accordance with the designated color for image editing designated by the operation key on the panel or the designated marker color. And output.

For example, when the designated color is red, R and G image data DR and DG are selected, and when the designated color is blue, G is selected.
The image data DG and DB of B and B are selected. When the designated color is red or blue, the R and B image data DR, D
B is selected.

The two-color image data selected by the selector 211 are timed by the first-in first-out delay memory 212, and then added to the color discrimination section 213 as an address input.

Here, the delay memory 212 is provided to compensate for the deviation of the output timing of the signal S0 due to the arrangement of the CCD arrays 16R, 16G and 16B of the image sensor 16, and in accordance with the read control of the CPU 201, 8 bits are provided. Data is delayed by the data transmission time corresponding to the sub-scanning time of 24 lines at the maximum.

The color discriminator 213 uses the two-color image data and C
2-bit designated color data D1 input from the PU 201
On the basis of the address designation by 2 and 2, the color of the original image is discriminated for each pixel and the color discrimination data DC is output.

The color discriminating section 213 is a ROM storing a color discriminating table corresponding to the designated color, and the designated color data D1.
2 bits indicating the value of the color discrimination data DC to be output at the address positions designated by the values "0" to "3" of 2 and the values "0" to "255" of the image data of the two colors, respectively. The data of is stored.

The erroneous discrimination correction unit 214 outputs the color discrimination data DC corresponding to the pixel of interest output from the color discrimination unit 213,
Color discrimination data DC corresponding to pixels around the pixel of interest
Is corrected and output as final color discrimination data Yc.

Therefore, the portion (marker) written by the marker pen of a color different from the color of the original image is
By inputting the color of the marker pen from the operation key, the color discrimination data Yc of a specific value, for example, the value "1" becomes the marker signal Yc. It is also possible to specify the color of the marker pen to be used in advance and to specify the color automatically by specifying the marker edit mode.

Further, the erroneous discrimination correcting section 214 outputs an image presence signal Yo for each pixel corresponding to an image portion which is not the background portion (background portion) of the document for the thickening processing described later. .. That is, the pixel portion to which the image present signal Yo is output is the image portion, and the pixel portion to which the image present signal Yo is not output is the base portion. This image signal Yo
Is detected by an area discriminating unit (not shown) so as to become "1" when the density of the original image exceeds a threshold value set to be higher than the background density.

The editing area discriminating section 215 is provided with an erroneous discrimination correcting section 2
14 outputs the marker signal Yc and the image-present signal Y
Based on o, it outputs a marker signal Ym for erasing the marker from the original image, detects a marker area surrounded by the marker, and outputs a marker area signal EE.

FIG. 5 is a block diagram of the editing area discrimination section 215.

The editing area discrimination section 215 includes a noise filter 222, a thickening processing section 223, and a marker area detection section 22.
4 and a selector 225.

The noise filter 222 includes the erroneous discrimination correction unit 2
The marker signal Ymi corresponding to only the marker by removing the noise included in the marker signal Yc output from
Is output.

The thickening processing unit 223 performs processing for thickening the marker signal Ymi only to the background side in order to prevent omission when the marker is erased from the original image and also to prevent thinning of the image. The marker signal Ym is output. The noise filter 222 and the thickening processing unit 223
The mask filter unit 221 is configured by.

FIG. 1 shows a mask filter section 22 according to the present invention.
1 is a circuit diagram, and FIG. 8 is a timing diagram for explaining the operation of the mask filter unit 221. However, the marker signals Ymi and Ym are delayed with respect to the marker signal Yc, respectively, but the delay amount is ignored in FIG.

The marker signals Yc, Ymi, and Ym originally mean that the state value is "1", but in the following description, the state value is either "1" or "0". It may also refer to the signal state at each location without asking.

The mask filter section 221 includes a shift register 231, AND circuits 232 to 235, and an OR circuit 23.
6, shift registers 237 and 238, selector 239,
OR circuit 240, AND circuit 241, knot circuit 242
It consists of

The black circles attached to the shift registers 231 and 238 indicate that the portions are signals corresponding to the target pixel.

The marker signal Yc input to the noise filter 222 is sequentially delayed by one pixel by the shift register 231 in synchronism with the clock signal CLK for each pixel. Minute marker signals Yc (pixel data) are simultaneously output in parallel.

These seven marker signals Yc are input to AND circuits 232 to 235 every four consecutive pixels,
When the marker signals Yc for four consecutive pixels are "1", the outputs of the AND circuits 232 to 235 are "1".

Therefore, when the marker signal Yc is continuous for four pixels or more, the OR circuit 236 outputs the corresponding marker signal Ymi as "1",
When the number of pixels is not continuous, the marker signal Ymi is "0" and is not output. As a result, the marker signal Yc that is not continuous for four pixels or more is cut as noise.

That is, for example, when the positions of the CCD arrays 16R, 16G and 16B of the image sensor 16 are deviated, the photoelectric conversion signals S0 of the respective colors output from them do not coincide with each other, so that the edge portion of the image is A thin band-shaped noise (marker signal Yc) is output by erroneous color discrimination.

Noise may also occur due to unevenness of the exposure lamp 12. Since the width of these noises is about 3 pixels or less, the noise filter 222
Therefore, the image is prevented from being erroneously edited by the image editing unit 205 or the like.

In the example of FIG. 8, the marker signal Yc at the central portion
Since b has only two pixels, it is cut as noise. On the other hand, since the width of the normal marker signal Yc due to the marker is usually about 16 pixels, normal image editing is performed without being affected by the noise filter 222.

The marker signal Ymi output from the noise filter 222 is sequentially delayed pixel by pixel in synchronization with the clock signal CLK by the shift register 238, and the marker signal Ymi of the target pixel is input to the A terminal of the selector 239. Then, the marker signal Ymi of each one pixel before and after the pixel of interest is input to the OR circuit 240.

On the other hand, the image presence signal Yo from the erroneous discrimination correction unit 214 is delayed by the shift register 237 to be synchronized with it, then inverted by the knot circuit 242 and input to the AND circuit 241.

Therefore, when one of the marker signals Ymi of each one pixel before and after the target pixel is "1" and the target pixel is not the image portion, that is, the base portion, the AND circuit 241 outputs "1". Is output.

The selector 239 outputs the marker signal Ymi of the pixel of interest input to the A terminal when "0" is input to the select terminal S, and the B signal when "1" is input to the select terminal S. The signal of "1" input to the terminal is output.

Therefore, when the pixel of interest is the marker signal Ymi of "1", the selector 239 always outputs the marker signal Ym of "1" in correspondence with this.
When the pixel of interest is the part of "0" adjacent to the marker signal Ymi, the pixel of interest is "1" when it is the base part and is "0" when it is the image part.

That is, the marker signal Y in which "1" is continuous
When mi is set as one block, one pixel before and after the block adjacent to the block is set to "1" only when it is the base portion.

As a result, as shown in FIG. 8, a marker signal Ym obtained by thickening the marker signal Ymi by one pixel only on the background side is obtained.

In this way, when the marker is erased from the original image, the background side is erased by an extra one pixel to prevent omission of erasure, and only the marker portion is erased on the image side. Image thinning is prevented.

On the image side, even if there is some erasure omission, there is no problem because it is not so noticeable. Further, although one pixel is additionally erased on the background side, two or more pixels may be erased.

Next, the marker area detection unit 224
On the basis of the marker signal Ym for each line continuously output from the mask filter unit 221, the marker area is real-time in units of one pixel for each line in the main scanning direction of the original image and in units of two lines in the sub scanning direction. And outputs the marker area signal EE.

FIG. 6 is a block diagram of the marker area detecting unit 224, and FIG. 9 is a timing chart of signals of each unit of the marker area detecting unit 224.

In the drawings and the description, parentheses after symbols indicating signals or data indicate that the marker signal Ym currently input to the marker area detection unit 224 corresponds to the current line (the 2nth line). In this case, the timing relationship with it is shown in line units.

Further, FIG. 9 shows an example of the marker Mk written by the marker pen, and the signal state based on the marker Mk is shown. The marker Mk is, for example, written by a marker pen having a relatively light color such as red, pink, and blue, and an inner region including each marker Mk and surrounded by the marker Mk is a marker region ME.

In FIG. 6, the marker area detecting section 224
Is a FIFO memory 251, 262, a counter 252,
253, selectors 254, 263, 264, memory 25
5, D flip-flop 256, OR circuits 257 and 26
1, an AND circuit 258, gate circuits 259 and 260, an edit selection unit 265, and a line control unit 266.

The detection operation in the marker area detection section 224 is performed by the marker area signal EE (2n-2) two lines before.
, The section state data SS is synchronized with the marker signal Ym (2n) input from the mask filter unit 221.
When the first cycle (write cycle) of writing (2n) into the memory 255 is performed, it is 1 more than the marker signal Ym (2n).
The section state data SS (2n-1) from the memory 255 is synchronized with the marker signal Ym (2n-1) delayed by the line.
And the read section state data SS
Second, which synthesizes (2n-1) and the marker signal Ym (2n-1) and outputs a marker area signal EE (2n-1)
Cycle (read cycle).

The marker area signal EE (2n-1) output in the second cycle is further delayed by one line by the FIFO memory 262, and the marker area signal EE (2n-1) is delayed.
n-2), which is referred to in the next first cycle.

The first cycle and the second cycle are alternately switched by the line synchronization signal TG first output for each line. The marker area signal EE is detected once for two cycles of the first cycle and the second cycle, and after being delayed by one line from the marker signal Ym input to the marker area detection unit 224, two lines are detected. It will be output over minutes.

The FIFO memory 251 stores and outputs the marker signal Ym for one line, and the marker signal Ym is delayed by one line.

The counter 252 counts up at the rising edge of the marker signal Ym. The count value of the counter 252 becomes an address for writing the section state data SS into the memory 255 in the first cycle.

The counter 252 divides each line of the document image into a plurality of sections divided by the marker signal Ym, and gives a count value as a section number NS to each section.

The counter 253 receives the marker signal Ym (2
marker signal Ym (2
Count up at the rising edge of n-1). The count value of the counter 253 is the memory 2 in the second cycle.
It becomes an address for reading the section state data SS written in 55.

These counters 252 and 253 are reset by the line synchronization signal TG first output for each line. In addition, these counters 252, 25
3 is a maximum of 1 corresponding to the number of pixels of the image sensor 16.
If there are 2 bits, there is no problem, but if considering the number of markers Mk to be actually written, about several bits is sufficient.

The selector 254 is switched by the R / W signal from the line control unit 266, and the counter 252.
Alternatively, the count value of 253 is selected and output. .

The memory 255 is addressed by the output from the selector 254, the read operation and the write operation are switched by the R / W signal from the line controller 266, and the data is read at the rising edge of the clock signal CLK during the write operation. Is written.

That is, in the above-mentioned first cycle, R /
The W signal results in a write operation and is addressed by the count value of counter 252. Therefore,
In the memory 255, the content (section state data SS) written immediately before the count value of the counter 252 is counted up is stored as the section state data SS at that address (section number NS).

In the second cycle, the read operation is performed by the R / W signal, the section state data SS (2n-1) stored in the memory 255, which is addressed by the count value of the counter 253, is read out.

The gate circuits 259 and 260 are for switching the flow of the section state data SS to the memory 255 in the first cycle and the second cycle, and are controlled by the line controller 266.

On the other hand, the marker signal Ym is input to the clock terminal of the D flip-flop 256, and
Since the D input terminal of the D flip-flop 256 is connected to the power supply and "1" is always input, the D flip-flop 256 is set at each rising edge of the marker signal Ym, and is reset if there is an output from the AND circuit 258. To be done.

The AND circuit 258 has a marker signal Ym.
And the marker area signal E of the previous line detected one time before
Since the logical sum with E (2n−2) is input, these marker signal Ym and marker area signal EE (2n−)
When both 2) become "0", the D flip-flop 256 is reset.

Of the output values from the D flip-flop 256, the section state data indicating whether the final output value in each section is the inner state section corresponding to the marker area or the outer state section corresponding to the outside of the marker area. It is SS. When the section state data SS is “0”, it is an outside state section,
In the case of "1", it is an inner state section.

That is, in the D flip-flop 256, in each section delimited by the marker signal Ym, that is, in each section given the section number NS by the above-mentioned counter 252, the portion other than the marker is the marker area of the previous line. When it overlaps with the outside, that is, when it overlaps the outside with respect to the marker area signal EE (2n−2), the section is determined to be the outside state section, “0” is output, and other sections are output. It is judged as the inner state section and "1" is output.

Here, in reality, the D flip-flop 25
Although the output of 6 changes within each section, as described above, the final output value in each section is the section state data SS.
Is stored in the memory 255. The above is the operation of the first cycle.

The D flip-flop 256 is reset when the line synchronization signal TG is input.

Next, in the second cycle, the memory 2
The section state data SS (2n-1) stored in 55 is read, and the OR circuit 261 outputs the marker signal Ym.
(2n-1).

As a result, the marker area signal EE (2
n-1) is obtained. That is, this marker area signal E
E (2n-1) is a signal that becomes "1" in the one line (the second nth line) corresponding to the region including the marker and surrounded by the marker, and is input to the marker region detection unit 224. It has a timing delay of one line with respect to the marker signal Ym.

This marker area signal EE (2n-1)
Is further delayed by one line by the FIFO memory 262, and the marker area signal E is delayed in the next first cycle.
It is input to the OR circuit 257 as E (2n-2).

Under the control of the line control unit 266, the selector 263 has the FIFO memory 2 in the first cycle.
The marker area signal EE (2n-2) from 62 is output, and the marker area signal EE (2n-1) from the OR circuit 261 is output in the second cycle.

Therefore, to the selector 264, the marker area signal EE (2n-1) is delayed by one line with respect to the input marker signal Ym, and the marker area signal EE (2n-2) having the same content is delayed by two lines. ) Are output respectively. That is, the marker area signal EE is output and updated in units of two lines.

The selector 264 outputs the edit mode signal md5.
Is in the color edit mode, the marker signal Ym is in the marker edit mode, and the marker area signal EE is in the edit mode.
Select each and output.

The edit selection section 265 receives the edit mode signal md.
6 to md8, the marker signal Ym is processed by selecting inversion or non-inversion of the area, the presence or absence of editing, etc.
Alternatively, the marker area signal EE is output as an edit signal.

As described above, according to the marker area detecting section 224, one line of the original image is divided into a plurality of sections by the marker signal Ym, and each section is discriminated as an inner state section or an outer state section. Since the section state data SS is created, the section state data SS is stored in the memory 255, and the marker area is detected based on the section state data SS read from the memory 255, the capacity of the memory 255 can be small. With counter 2
Since the maximum count values such as 52 and 253 can be small, the structure is simple and the cost is low.

Here, returning to FIG. 5 again, the marker signal Ym output from the thickening processing unit 223 is the selector 22.
5 and the edit mode signal md3 is in the marker edit mode, the marker signal Ym is input to the image editing unit 20.
5, and the marker is erased from the image data DG.

FIG. 7 is a circuit diagram of the marker erasing circuit 226 of the image editing unit 205, and FIG. 10 is a diagram showing the state of the image data DG when the marker erasing process is performed by the marker erasing circuit 226.

The marker erasing circuit 226 inputs the background density data UN and the image data DG to the selector 271.
Consists of. The selector 271 sets the background density data UN to the marker signal Y when the marker signal Ym is input.
When m is not input, the image data DG is selected and output as the image data DG.

That is, of the input image data DG,
Since the position corresponding to the marker signal Ym is the marker Mk, that portion is replaced with the background density data UN of the original image, whereby the marker is erased and the erasure trace is not unnatural.

That is, as shown in FIG. 10 (A), for one line in the main scanning direction, two large density peaks corresponding to an image such as a character appear in the central portion, and the markers Mk are provided on both sides thereof. In the case where a small concentration peak appears due to, the portion of the marker Mk corresponds to the marker signal Ym.
By substituting with N, as shown in FIG. 10B, image data DG with flat density in which no mark of the marker Mk appears is obtained.

When edge enhancement processing is performed on the image data DG in the filter section 207, for example, the edge portion of the image is well enhanced as shown in FIG.

If the marker Mk is not replaced with the background density data UN and is simply replaced with white data as in the conventional case to erase the data, FIG.
As indicated by a broken line, the marker Mk becomes whiter than the background density and stands out from the background, and the edge is emphasized to appear as a thin line, resulting in a more unnatural image.

As described above, the marker erasing circuit 226 allows the marker Mk added to the original for image editing.
Can be surely erased from the original, and the erased image can be restored to an image having natural gradation.

Particularly when reading and copying an original such as newspaper, blueprint, colored paper, recycled paper, etc., the background density is high, so the background density data UN by the marker erasing circuit 226.
The replacement with is extremely effective.

Now, the detection processing of the background density data UN will be described with reference to the flowchart shown in FIG.

The background density data UN is detected by prescanning the original. The preliminary scan is started (step # 11), and the density data of the original is sampled until the end of the original (steps # 12, 13).
The density data is black when the minimum value is “0” and white when the maximum value is “255”.

For the sampled density data, the frequency H for each density value x (= 0 to 255)
(X) is obtained (step # 14).

Next, the maximum density data N0 allowable as the background density is substituted into the variable N corresponding to the density level and the variable UN corresponding to the background density data (step # 1).
5). The maximum density data N0 is the maximum allowable density, and is therefore the minimum allowable data value. The maximum density data N0 is set by the initial setting.

Frequency H (N) due to variable N and variable UN,
H (UN) is compared with each other, and when the frequency H (N) is larger (Yes in step # 16), the value of the variable N is substituted for the variable UN (step # 17).

Then, the variable N is incremented by 1 (step # 18), and this is executed until the variable N reaches 255 (step # 19).

As a result, the frequency H (x) is the highest between the maximum allowable density and the white with the lowest density.
Since the density data having a high value is obtained in the variable N, this is used as the background density data UN.

In the above embodiment, the marker signal Y
Although the counters 252 and 253 are counted up at the rising edge of m and the D flip-flop 256 is set at the same time, the section is divided at each rising edge of the marker signal Ym (the dividing method A in FIG. 12).
As shown in the classification method B in FIG. 12, the marker signal Ym
It is also possible to perform section segmentation for each trailing edge, or as shown in the segmentation method C in FIG. 12, segmentation can be performed for both the rising edge and the trailing edge of the marker signal Ym.

In particular, when the sections are divided at both the rising edge and the falling edge of the marker signal Ym, each of the sections is either the portion corresponding to the marker Mk or the other portion.

Therefore, in this case, the marker M
When the area including k and surrounded by the marker Mk is set as the marker area ME, and when the area filled by the marker Mk is set as the marker area ME, only the section determined to be the outside state section is directly outside the marker area. Become.

For example, in the example of the segmentation method C shown in FIG. 12, the sections with section numbers 1, 3, 5, 7, and 9 are markers M.
k, the section numbers 2 and 6 are the inner state sections, and the section numbers 0, 4, 8 and 10 are the outer state sections, so only the section numbers 0, 4, 8 and 10 are Is outside the marker area, and all other sections are the marker area ME.

On the other hand, when the area surrounded by the markers Mk excluding the marker Mk is set as the marker area ME, only the section determined to be the internal state section becomes the marker area ME as it is.

The circuit configuration of the marker area detection unit 224 may be changed appropriately according to the section division method.

In the above-described embodiment, the marker signal Ym for one line is stored in the FIFO memory 251, and the counter 253 counts it so that the write address and the read address to the memory 255 are matched. .

That is, by the FIFO memory 251,
The position in one line of each section for reading the section state data SS from the memory 255 is stored. For example, a counter that counts the clock signal CLK and a count value when the marker signal Ym is input are stored. The position of each section is stored as the number of pulses (the number of pixels) of the clock signal CLK in one line by the memory to be stored, and when reading from the memory 255, the clock signal CLK in one line is stored. A carry pulse may be output each time the counting counter reaches the previously stored count value, and the memory 255 may be addressed by the count value of the carry pulse.

The memory 255 using these counters
In addressing, the count value of the counter may be added or multiplied by an appropriate constant.

In the above embodiment, the original platen glass 1
The scanner 11 scans the image of the original placed on the scanner 8 to obtain the image data DG and the marker area signal EE. The original image is temporarily stored in an appropriate image memory, The marker area signal EE may be obtained while reading.

In the above embodiment, the noise filter 2
22, the circuit configuration of the thickening processing unit 223, the editing area determination unit 215, and the signal processing unit 20, the signal timing of each unit, the configuration of the copying machine 1, and the like can be variously changed other than those described above. Further, the present invention can be applied to various image editing processes other than erasing a marker.

[0133]

As described above, according to the present invention, it is possible to prevent erroneous deletion of the marker and prevent the image portion from becoming thin so that a clear edited image can be obtained.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a mask filter unit according to the present invention.

FIG. 2 is a sectional front view showing a schematic configuration of a copying machine having a thickening processing unit according to the present invention.

FIG. 3 is a plan view of an image sensor.

FIG. 4 is a block diagram showing a configuration of a signal processing unit.

FIG. 5 is a block diagram of an edit area determination unit.

FIG. 6 is a block diagram of a marker area detection unit.

FIG. 7 is a circuit diagram of a marker erasing circuit of an image editing unit.

FIG. 8 is a timing chart for explaining the operation of the mask filter unit.

FIG. 9 is a timing chart of signals of respective parts of the marker area detection unit.

FIG. 10 is a diagram showing a state of image data when a marker erasing process is performed by the marker erasing circuit.

FIG. 11 is a flowchart showing a background density data detection process.

FIG. 12 is a diagram showing various methods of dividing a section in one line.

[Explanation of symbols]

 1 Copying Machine (Image Editing Device) 213 Color Discrimination Unit (Specific Color Image Detection Unit) 223 Thickening Processing Unit (Density Conversion Unit) 226 Marker Erasing Circuit (Density Conversion Unit) DG Image Signal (Image Information) Yc, Ymi Marker Signal (Image part of specific color)

Claims (1)

Claim: What is claimed is: 1. A specific color image detecting unit for detecting an image portion of a specific color in input image information, and a background region of low density and an image of high density of the image information. An area discriminating unit for discriminating an area, and a density of a portion of the image portion of the specific color and a portion adjacent to the image portion which is discriminated as the base area by the area discriminating unit is converted into a predetermined density. An image editing apparatus comprising: a density converting unit.