JP2000354150A - Image processor and image processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove a black frame area by one reading processing by holding image data of a read document by the line, detecting the continuous black pixel area from a starting position of reading, resetting continuous black pixels to appear on a continuous area from the starting position of reading of the same line and afterward whenever white pixel appears and invalidating the continuous black pixel area of each line which is finally left. SOLUTION: The image data formed by reading a document by every line is inputted in a line memory A101 or B102. In this case, count of the black pixel areas is started and a counter value M is decided when the white pixel appears by an M counter 103. Count of the black pixel areas is started by an N counter 104 when the black pixel appears next, a counter value is reset when the white pixel appears, such a process is repeated and the counter value N is decided at the point of time when the reading of one line is completed. Mask values of the lines are decided based on the counter values M, N by a mask M, N counters 105, 106 and an area to be decided by the mask value is masked and data is outputted by a mask part 107.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus and an image processing method for detecting a black frame area of a document and removing the detected black frame area.

[0002]

2. Description of the Related Art Conventionally, in a copying machine or the like, when a book document is placed on a document table and read, the document cover cannot be completely closed and external light may enter. Also,
Even if it is a normal document, if the document is read with the document cover opened, external light enters. In such a case, if a document smaller than the regular reading size is read, or if the document is placed at a position shifted from the regular reading position, a black frame may be formed around the recorded image on the copied recording paper. Become.

[0003] In order to erase the black frame, a technique of detecting a black frame area of a read original and converting it into white information has been conventionally known. In this technique, an operator selects an upper, lower, left, or right end area with an arbitrary width, and converts the selected area into white information.

[0004]

However, according to the above-mentioned prior art, the operator has to specify the width of the black frame to be removed each time by himself, and there is a problem that the operation is troublesome. Also, looking at the copied recording paper, the specified width is too large and necessary information is deleted,
If the specified width is too small and the black frame is still around, the operator must correct the specified width by intuition and repeat the copying again, which is a problem that the operation is very troublesome. is there. Furthermore, unless the correction of the designated width is repeated to some extent, it is not possible to properly remove the black frame corresponding to each document, and there is a problem that recording paper is wasted.

In order to solve such a problem, the same document is read twice, a black frame area is detected first, image data is read second, and the first image data is read from the second image data. There has also been proposed a technique of performing processing for invalidating a read black frame area to eliminate the intervention of an operator's operation.

However, with such a means, it is necessary to read the same document twice, and to remove black frames,
There is a problem that the reading time is doubled and the reading process is significantly slowed down.

The present invention has been made in view of such a problem, and in one reading process, an image capable of automatically detecting a black frame region of each document and removing the black frame region. It is an object to provide a processing device and an image processing method.

[0008]

In order to achieve the above object, the present invention holds image data of a read original in units of a line, detects a continuous black pixel area from a reading start position, and uses the same line. The continuous black pixels appearing after the continuous black pixel region from the reading start position are reset each time a white pixel appears, the last remaining continuous black pixel region is detected, and the continuous black pixels corresponding to each line are detected. Means of obtaining valid image data by invalidating the area is adopted.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An image processing apparatus according to a first aspect of the present invention has a storage means for holding image data of a read original in units of lines, and detects a continuous black pixel area from a reading start position of each line. The first means for resetting continuous black pixels appearing after the continuous black pixel area from the reading start position on the same line every time a white pixel appears, and detecting the last remaining continuous black pixel area (2) and means for obtaining effective image data by invalidating a continuous black pixel area corresponding to each line detected by the first means and the second means in each line.

According to this configuration, the black pixel regions at both ends are simultaneously detected while holding the image data of each line, and when outputting, the black pixel regions at both ends of each image data are output while invalidating the black pixel regions. Can automatically remove black pixel regions at both ends from image data in a single reading process, so that the operator does not bother to read the same document a plurality of times. The appropriate removal of the black frame region of the image data can be realized without delay.

According to a second aspect of the present invention, in the image processing apparatus according to the first aspect, the first means is such that black pixels continue even when a predetermined number of white pixels are detected. And the second means determines that black pixels are continuous even when a predetermined number of white pixels are detected.

With this configuration, even when a document is read in the halftone reading mode, the black frame area is erroneously detected erroneously and the black frame is inappropriately removed, and wasteful recording paper is not generated. Can be prevented.

An image processing apparatus according to a third aspect of the present invention comprises a first storage means for storing image data of a read original in units of lines, and a continuous black pixel area from a reading start position of each line. The first means for detecting, and the second means for resetting the continuous black pixels appearing after the continuous black pixel area from the reading start position on the same line each time a white pixel appears, and detecting the last remaining continuous black pixel area Means for obtaining effective image data of each line by invalidating a continuous black pixel region corresponding to each line detected by the first means and the second means in each line; The second storage means for storing, and when writing each line to the second storage means, writing so that the start point of the effective area of each line after the second line matches the start point of the effective area of the first line. Adopts a configuration comprising a control means for controlling to change the viewing timing, the.

With this configuration, the starting point of the effective area can be aligned at the same position between the lines, so that not only the black frame area is removed in one reading process, but also when the original is bent and arranged. Even if there is, the curvature of the document can be properly corrected.

An image processing apparatus according to a fourth aspect of the present invention comprises a storage unit for storing image data of a read original in units of lines, and a storage unit for detecting a continuous black pixel area from a reading start position of each line. A second means for resetting a continuous black pixel appearing after the continuous black pixel area from the reading start position on the same line every time a white pixel appears, and detecting a last remaining continuous black pixel area; Means for obtaining effective image data by invalidating a continuous black pixel area corresponding to each line detected by the first means and the second means in each line; and obtaining image data of each line from the storage means. When reading, control means for controlling the read position so that the start point of the effective area of each line after the second line matches the start point of the effective area of the first line is adopted. .

According to this configuration, the starting point of the effective area can be aligned at the same position between the lines, so that not only the black frame area is removed in one reading process but also when the original is bent. Even if there is, the curvature of the document can be properly corrected.

According to a fifth aspect of the present invention, there is provided the image processing apparatus according to the third aspect, further comprising means for detecting whether the original is right-handed or left-handed, and wherein the control means comprises: In the case of, for the area before the line where the start point of the effective image data is the leftmost end, each line is written from the start point of the effective image data while being shifted by an interval from the reading start position of the first line to the start point of the effective image data. For the lines after the leftmost line, the timing is changed so that each line is written from the start point of the effective image data.

According to a sixth aspect of the present invention, in the image processing apparatus according to the third aspect, there is provided means for detecting whether the original is right-handed or left-handed. In the case of the first line, the line where the start point of the effective image data is the leftmost line is set as the first line, and thereafter, the start point of each line of the effective image data is aligned with the start point of the effective image data of this line. As for (1), the timing is changed so that each line is written from the start point of the effective image data.

With this configuration, when the original is read in a bent state, the starting point of the effective image data is aligned for all lines, so that the copied image is reproduced as a remarkably different upper end or lower end from the original image. In addition, it is possible to correct the skew of the document and to remove the black frame area while preventing the occurrence of the blackout.

According to a seventh aspect of the present invention, there is provided the image processing apparatus according to the fourth aspect, further comprising means for detecting whether the original is right-handed or left-handed. In the case of, for the area before the line where the start point of the effective image data is the leftmost end, each line is read from the start point of the effective image data while being shifted by an interval from the reading start position of the first line to the start point of the effective image data. On the other hand, for the area after the line at the leftmost end, each line is read from the start point of the effective image data.

According to an eighth aspect of the present invention, there is provided the image processing apparatus according to the fourth aspect, further comprising means for detecting whether the original is right-handed or left-handed, and wherein the control means comprises: In the case of the first line, the starting point of the effective image data is set as the first line, and thereafter, the starting point of the effective image data of each line is aligned with the starting point of the effective image data of this line. , Each line is read from the start point of the effective image data.

According to this configuration, when the original is read in a bent state, the starting points of the effective image data are aligned for all lines, so that the copied image is reproduced as a remarkably different upper end or lower end from the original image. In addition, it is possible to correct the skew of the document and to remove the black frame region while preventing the occurrence of the skew.

An image processing apparatus according to a ninth aspect of the present invention comprises: a first means for detecting a first continuous black pixel area from a reading start position of each line; A second means for resetting a continuous black pixel appearing after the continuous black pixel from each time a white pixel appears, and detecting a last remaining second continuous black pixel area, and a first means for a plurality of lines. Calculating a first difference between the continuous black pixel regions and a second difference between the second continuous black pixel regions;
A control unit that determines whether the original is right-handed or left-handed according to the magnitude of the first difference and the second difference.

With this configuration, it is possible to simultaneously detect the inclination of the document while reading the document.
Three detections, that is, the removal of the black frame area and the inclination direction of the document can be performed.

An image processing apparatus according to a tenth aspect of the present invention comprises: a first means for detecting a first continuous black pixel area from a reading start position of each line; A second means for resetting a continuous black pixel appearing after the continuous black pixel from each time a white pixel appears, and detecting a last remaining second continuous black pixel area, and a first means for a plurality of lines. A first difference of a continuous black pixel region and a second difference of the second continuous black pixel region are calculated, and whether the original is right-handed or left-handed depending on the magnitude of the first difference and the second difference. Judgment and the first
And a control unit for calculating a bending angle of the original document based on the difference between the original document and the second difference.

According to this configuration, the inclination of the original is simultaneously detected while reading the original, instead of temporarily storing the entirety of the read image data in the memory to detect the inclination. With this configuration, it is possible to perform four detections of image data acquisition, removal of the black frame area, and the direction of inclination of the document and the inclination angle thereof in parallel.

Further, a facsimile apparatus according to an eleventh aspect of the present invention employs a configuration including the image processing apparatus according to any one of the first to tenth aspects.

According to this configuration, the black pixel regions at both ends are simultaneously detected while holding the image data of each line, and when outputting, the black pixel regions at both ends of each image data are output while being invalidated. Can automatically remove black pixel regions at both ends from image data in a single reading process, so that the operator does not bother to read the same document a plurality of times. The appropriate removal of the black frame region of the image data can be realized without delay.

The image processing method according to a twelfth aspect of the present invention includes a step of holding image data of a read original in units of lines, a step of detecting a continuous black pixel region from a reading start position, and a step of A step of resetting continuous black pixels appearing after the continuous black pixel area from the reading start position each time a white pixel appears, and detecting a last remaining continuous black pixel area; Obtaining effective image data by invalidating the pixel area.

With this configuration, the black pixel regions at both ends are simultaneously detected while holding the image data of each line, and when outputting the image data, the black pixel regions at both ends of each image data are output while invalidating them so that the same line is output. Can automatically remove black pixel regions at both ends from image data in a single reading process, so that the operator does not bother to read the same document a plurality of times. The appropriate removal of the black frame region of the image data can be realized without delay.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. (Embodiment 1) An image processing apparatus according to Embodiment 1
In one reading process, a process of automatically removing black pixel regions at both ends from image data is performed.

FIG. 1 is a block diagram showing a schematic configuration of an image processing apparatus according to Embodiment 1 of the present invention. The line memory A101 and the line memory B102 hold image data of a read document every two lines in line units.
The M counter 103 is a leftmost mask width detection counter, and the N counter 104 is a rightmost mask width detection counter. The mask M counter 105 is a mask execution counter at the left end, and outputs “M + α” including the margin width α in the counter value M of the M counter 103. The mask N counter 106 is a mask execution counter at the right end, and outputs “L−N−α” including the margin width α in the counter value N of the N counter 104. This "L"
Is a reading range in the main scanning direction. The mask unit 107 masks and outputs an image signal.

Next, the concept of an image reading operation and an image writing operation in the image processing apparatus according to the first embodiment of the present invention will be described. FIG. 2 is a timing chart of an image reading operation and an image writing operation in the image processing apparatus according to Embodiment 1 of the present invention. First, an original is read line by line by a reading unit (not shown), and image data obtained by reading is input to the line memory A101 or the line memory B102. Writing to and reading from the line memory A101 or the line memory B102
It is performed as follows.

That is, as shown in FIG. 2, the read image data of the first line is written into the line memory A101, and at the same time, the counter value of the M counter 103 and the counter value of the N counter 104 for the first line are determined.
Next, the image data of the first line is read from the line memory A101. The read first line image data is masked and output. The value of this mask is M
Based on the counter value of the M counter 103, the N counter 1
Each of them is calculated based on the counter value of No. 04. Simultaneously with the reading of the image data of the first line, the image data of the second line is written into the line memory B102, and at the same time, the count value of the M counter 103 and the count value of the N counter 104 for the second line are determined.

Similarly, the image data of the second line is read from the line memory B102. The read image data of the second line is masked and output. The value of this mask is determined by the M mask counter 105 by the M counter 10.
Based on the counter value of 3, the N mask counter 106
Each is calculated based on the counter value of the N counter 104. Simultaneously with the reading of the image data of the second line, the image data of the third line is written into the line memory A101.
And the count value of the N counter 104 are determined.

As described above, since the mask area is determined based on the line to be masked by the line memory A101 and the line memory B102, masking can be performed without any problem even if the original is curved.

Next, the relationship between data input and masked output in the image processing apparatus according to Embodiment 1 of the present invention will be described. FIG. 3 is a timing chart showing an input / output relationship of data when there is no black in one line of image data in the image processing apparatus according to Embodiment 1 of the present invention. Hereinafter, the reading range L is read from the left. Since black exists from the leftmost end, when reading is started, the M counter 103 starts counting the black pixel area. The M counter 103 continues counting, and the M counter value M is determined at a portion where white first appears. After white continues, the first time black appears, the N counter 10
4 starts counting the black pixel area. N counter 10
No. 4 resets the counter value when white appears, but in this case, the N counter 104 continues counting because black continues. When the rightmost end is reached, the N counter value N is determined. The mask M counter 105 and the mask N counter 106 respectively calculate a value including a margin based on the counter values M and N, and determine the value of the mask in this line. When the value of the mask is determined, the mask unit 10
7 masks an area determined by the value and outputs data.

FIG. 4 is a timing chart showing an input / output relationship of data in a case where black is present in one line of image data in the image processing apparatus according to Embodiment 1 of the present invention. Since black exists from the leftmost end, when reading is started, the M counter 103 starts counting the black pixel area. The M counter 103 continues counting, and the M counter value M is determined at a portion where white first appears. After white continues, N counter 10 when black first appears
4 starts counting the black pixel area. However, since black appears on the line and white appears on the line, the N counter 104 resets the counter value when white appears. Next, when black appears, the N counter 104 starts counting the black pixel area again. However, since white appears again, the counter value is reset. This is repeated, and the N counter value N is determined at the stage where the rightmost end of the reading range L is reached while black continues. Mask M counter 10
5 and the mask N counter 106 calculate a value including a margin based on the counter values M and N, respectively, and the value of the mask in this line is determined. When the value of the mask is determined, the mask unit 107 masks an area determined by the value and outputs data.

FIG. 5 is a timing chart showing the data input / output relationship when the image data of one line is white from the first pixel in the image processing apparatus according to Embodiment 1 of the present invention. Since black does not exist from the leftmost end, the M counter 103 does not count the black pixel area even when reading is started. In this case, the M counter value M becomes 0. After white, N appears when black first appears
The counter 104 starts counting the black pixel area. However, even in this line, since black is interrupted on the way and white appears, the N counter 104 resets the counter value when white appears. Next, when black appears, the N counter 104 starts counting the black pixel area again.
Since white appears again, the counter value is reset. This is repeated, and the N counter value N is determined at the stage where the rightmost end of the reading range L is reached while black continues. The mask M counter 105 and the mask N counter 106 respectively
A value including a margin is calculated based on the counter values M and N, and a mask value in this line is determined. When the value of the mask is determined, the mask unit 107 masks an area determined by the value and outputs data. In this case, the value of the mask M counter 105 is the margin width α
Only.

Thus, while simultaneously holding the image data of each line, the black pixel regions at both ends are detected, and when outputting, the black pixel regions at both ends of each image data are output while invalidating them, so that the same line is output. In a single reading process, the process of automatically removing the black pixel regions at both ends from the image data can be performed, so that the operator is not bothered and the same document is not read a plurality of times, so that the reading speed is delayed. Thus, it is possible to realize appropriate removal of the black frame region of the image data without performing the above operation.

FIG. 6 is a timing chart showing the detection of a black area when the input image data is halftone in the image processing apparatus according to the first embodiment of the present invention. As shown in the first row of FIG. 6, when the portion corresponding to the black frame area in the input image data is binarized, the image data becomes all black as shown in the second row. For halftone images, the error diffusion method or dither method is used to express the gradation, so unnecessary light is mixed in as in the case where reading is performed with the cover of the document opened. Then, the portion which is originally a black frame region is not completely black, and white pixels are scattered in some places. In the third row of FIG. 6, this is expressed on a line. In such a case, when white appears, M
The counter 103 stops counting or the N counter 1
When the counter 04 resets the counter value, it is recognized that the black frame area is smaller than the actual area, and as a result, it becomes impossible to appropriately remove the black frame. Therefore, with respect to halftone data, even if white pixels are detected, if the number is equal to or less than a predetermined number, it is determined that black is continuous. That is, as shown in the fourth row of FIG. 6, the M counter 103 continues counting black pixels even when detecting white pixels, and determines the M counter value when continuous white pixels are detected. Although not shown, even if the N counter 104 detects a white pixel, if the number is equal to or smaller than a predetermined number, it is regarded that black is continuous, and the black pixel is continuous and the reading range is not changed. When reaching the rightmost end, the N counter value is determined.

Thus, even when an original is read in the halftone reading mode, an erroneously short black frame area is erroneously detected and inappropriate black frame removal is performed, thereby preventing wasteful recording paper from being generated. can do.

Next, an example of use of the image processing apparatus according to the first embodiment of the present invention will be described with reference to FIG. FIG. 7 is a diagram illustrating an example of use of the image processing apparatus according to the first embodiment of the present invention, and FIG. 7A is a diagram illustrating a state where a document is placed obliquely. Since the image processing apparatus according to the first embodiment of the present invention detects a black frame for each line based on the M counter value and the N counter value, even if the document is placed obliquely as described above, the edge of the document is automatically detected. It is possible to mask surrounding black in an appropriate range by recognizing the situation. However, the original data is not corrected for the image data.

FIG. 7B is a diagram showing a case where the document is shifted from the reading range. Even in such a case, the image processing apparatus according to the first embodiment of the present invention detects the black frame for each line based on the M counter value and the N counter value. Can remove the black frame.

(Embodiment 2) Next, an image processing apparatus according to Embodiment 2 of the present invention will be described. The image processing apparatus according to the second embodiment not only removes the black frame region in one reading process, but also appropriately corrects the curving of the document even when the document is bent.

FIG. 8 is a block diagram showing a schematic configuration of an image processing apparatus according to Embodiment 2 of the present invention. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The mask generation unit 801 generates a signal for masking an image signal, and
2 generates an enable signal whose timing is shifted to change the write position of the page memory. Further, the inclination direction correction line detection unit 803 detects the position from which the image is to be corrected according to the direction of the inclination of the document.
Step 04 selects the necessity of correction based on the above result.

Next, the relationship between data input and masked output in the image processing apparatus according to the second embodiment of the present invention configured as described above will be described. FIG. 9 is a timing chart showing an input / output relationship of data in the image processing apparatus according to Embodiment 2 of the present invention. A reading unit (not shown) starts reading the document based on an enable input signal for restricting the reading range of the document. In the case of this document, since black exists from the leftmost end, the M counter 1
03 starts counting the black pixel area. M counter 1
03 continues counting, and M is the part where white first appears.
The counter value M is determined. After black continues, the N counter 104 starts counting the black pixel area when black first appears. The N counter 104 resets the counter value when white appears, but in this case, since black continues, the N counter 104 continues counting. When the rightmost end is reached, the N counter value N is determined. The mask M counter 105 and the mask N counter 106 calculate a value including a margin based on the counter values M and N, respectively. Here, a state in which the third line is read is shown, and the original is placed to the left, and as shown, the leftmost black frame area increases as the line advances.

The enable generation unit 802 generates an enable signal for changing a write position to a page memory (not shown) according to the M counter value. In the first line, when the value M of the M counter is obtained, the enable generation unit 8
No. 02 changes and outputs the enable signal based on the M so that the width from the writing position to the first appearing white pixel is always M for the second and subsequent lines. That is, the timing of writing to the page memory is changed so that the start point of the effective area in each line after the second line matches the start point of the effective area in the first line.

At the same time, the inclination direction correction line detecting unit 803
Detects the position from which to correct according to the direction of the inclination of the document, and outputs the detection result to the selector 804.
The selector 804 selects and outputs the enable signal generated by the enable generation unit 802 based on the input signal relating to the inclination of the original when the original is bent,
If the original is not bent, an enable signal used in normal reading is selected and output.

On the other hand, mask generation section 801 generates a signal for masking an image signal, and mask section 107 masks an area determined by the value and outputs data.

As a result, the starting point of the effective area can be aligned at the same position between the lines, so that not only the black frame area is removed in one reading process but also the original is bent. However, it is possible to properly correct the skew of the original.

Next, an example of use of the image processing apparatus according to the second embodiment of the present invention will be described with reference to FIG.
FIG. 10 is a diagram illustrating a use example of the image processing apparatus according to the second embodiment of the present invention, and FIG. 10A is a diagram illustrating a state where a document is placed obliquely. The image processing apparatus according to the second embodiment of the present invention automatically recognizes the edge of the document, masks the surrounding black, and corrects the curvature of the document in the main scanning direction. That is, a black frame is detected for each line based on the M counter value and the N counter value, and the starting point of the effective area is aligned at the same position between the lines. Therefore, even if the document is placed obliquely as shown in FIG. , It is possible to correct the bending of the original. In order to correct image data,
If the image in the effective area of the document is slightly distorted, but the curvature of the document is small, there is almost no effect, so the correction for the curvature of the document functions effectively.

FIG. 10B is a diagram showing a range to be corrected and a range not to be corrected when the document is shifted left or right with respect to the reading range. In the second embodiment, when the original is left-turned, the line where the start point of the effective image data is the leftmost end is set as the first line, and thereafter, the effective image data of each line is set as the start point of the effective image data of this line. Align the starting point of the data. On the other hand, if the start point of each line in the image area before the leftmost line is aligned with the start point of the first line, an appropriate image cannot be obtained.
Each line is written from the start point of the effective image data. On the other hand, when the original is right-turned, the effective image data is shifted from the reading start position of the first line to the start of the effective image data in the area before the line where the effective image data start point is the leftmost end. Each line is written from the start point of the line, and after the line at the leftmost end, if the distance from the reading start position to the start point of the effective image data is shifted, an appropriate image cannot be obtained. Write.

In this way, when the original is read in a bent state, the start point of the effective image data is aligned for all the lines, so that the copied image is reproduced as being significantly different from the original image at the upper end or the lower end. , The skew of the document can be corrected, and the black frame region can be removed.

(Embodiment 3) Next, an image processing apparatus according to Embodiment 3 of the present invention will be described with reference to the drawings. The image processing apparatus according to the third embodiment not only removes the black frame area in one reading process, but also appropriately corrects the curving of the document even when the document is bent.

FIG. 11 is a block diagram showing a schematic configuration of an image processing apparatus according to Embodiment 3 of the present invention. In addition,
The same configurations as those in the first and second embodiments are denoted by the same reference numerals, and description thereof is omitted. The line memory read address control unit 1001 includes a line memory A10
1 and the line memory B102 are controlled to change the reading position. Further, the output signal of the M counter 103 and the output signal of the tilt direction correction line detection unit 803 are input to the line memory read address control unit 1001.

Next, the relationship between data input and masked output in the image processing apparatus according to Embodiment 3 of the present invention configured as described above will be described. FIG.
FIG. 9 is a timing chart illustrating an input / output relationship of data in the image processing apparatus according to the second embodiment of the present invention. Based on the enable input signal that regulates the reading range of the original,
A reading unit (not shown) starts reading the document. In the third embodiment, the enable input signal has a fixed value.

In the case of the document read here, since black exists from the leftmost end, the M counter 103 starts counting the black pixel area. The M counter 103 continues counting, and the M counter value M is determined at a portion where white first appears. After black continues, the N counter 104 starts counting the black pixel area when black first appears. The N counter 104 resets the counter value when white appears. In this case, since black continues, the N counter 1
04 continues counting. When the rightmost end is reached, the N counter value N is determined. The mask M counter 105 and the mask N counter 106 calculate a value including a margin based on the counter values M and N, respectively. Here, the third
This shows a state in which the line has been read, and the original is placed to the left, and as shown in the figure, the leftmost black frame area increases as the line advances.

Line memory read address control unit 100
When the value M of the M counter is obtained in the first line, the width from the reading position to the effective area of the document is always M for the lines subsequent to the second line based on this value M.
The read positions from the line memories A101 and B102 are changed so that That is,
The read position is changed so that the start point of the effective area in each line after the second line matches the start point of the effective area in the first line.

When the mask value is determined by the mask M counter 105 and the mask N counter 106, the mask unit 107 masks the area determined by the value.
Output data.

As a result, the starting point of the effective area can be aligned at the same position between the lines, so that not only the black frame area is removed in one reading process but also the original is bent. However, it is possible to properly correct the skew of the original.

As in the case of Embodiment 2 shown in FIG. 10, an example of use of the image processing apparatus according to Embodiment 3 of the present invention is a case where an original is placed obliquely or an original is shifted. It can also be applied when

(Embodiment 4) Next, an image processing apparatus according to Embodiment 4 of the present invention will be described with reference to the drawings. The image processing apparatus according to the fourth embodiment removes the black frame area by one reading operation and detects the inclination direction of the document.

FIG. 13 is a block diagram showing a schematic configuration of an image processing apparatus according to Embodiment 4 of the present invention. An M counter 1301 is a mask width detection counter at the left end,
The N counter 1302 is a rightmost mask width detection counter. Latch circuits 1303, 1305, 1307
Is a previous line latch circuit for comparing the previous line with the current line, and includes comparators 1304, 1306, 1308
Compares the previous line with the current line. Further, the comparator 13
09 compares the output signals of the comparator 1306 and the comparator 1308. Condition determination unit 1310 determines a range to be corrected based on input signals from comparators 1304 and 1309.

Next, the operation of the image processing apparatus according to Embodiment 4 of the present invention configured as described above will be described. When reading means (not shown) starts reading a document, the read image data is input to the M counter 1301 and the N counter 1302. The functions of M counter 1301 and N counter 1302 are the same as in the first embodiment. The output of the M counter 1301 is input to the latch circuits 1303 and 1305 for the previous line A, and the current line B is input to the comparators 1304 and 1306. Comparator 1304
Compares the value of the M counter 1301 in the previous line A with the value of the M counter 1301 in the current line B, and outputs the comparison result to the condition determination unit 1310.

The comparator 1306 is provided with the M counter 13
The input signal from 01 and the input signal from latch circuit 1305 are compared, and the comparison result is output to comparator 1309.
The comparator 1308 compares the input signal from the N counter 1302 with the input signal from the latch circuit 1307 and outputs a comparison result to the comparator 1309. Here, the comparison operation in the comparator 1309 will be described with reference to FIG.

FIG. 14 is a timing chart of the comparator 1309 in the image processing apparatus according to Embodiment 4 of the present invention when detecting the bending direction of a document. FIG.
In, the previous line is the current line. The comparator 1306 calculates a difference x from the M counter value and the M counter value. Also, the comparator 1308
The difference y is calculated from the N counter value and the N counter value. The comparator 1309 compares the magnitudes of x and y to determine the inclination direction of the document. In the case of the original shown in FIG. 14, since the comparison results in x> y, the inclination direction of the original is
Judge as "right". Comparator 1309 outputs this determination result to condition determination section 1310.

The condition judging unit 1310 determines that the leftmost black pixel area of the read current line B is larger than the leftmost black pixel area of the previous line A based on the input signals. If it is larger, the current line B is corrected, and if smaller, it is determined that no correction is performed. This is because, as described in the second embodiment, in the case of a left turn, the upper right portion of the document is aligned to the left end by the correction, so that an appropriate image cannot be obtained. For this reason, in the case of a left turn, no correction is made for the portion that protrudes to the upper right with respect to the horizontal, and correction is made for the other portions. Similarly, if the original is right-turned and the leftmost black pixel area of the read current line B is larger than the leftmost black pixel area of the previous line A, the condition determination unit 1310 determines that the current line B Is not corrected, and when it is smaller, it is determined to correct. In the case of a right turn, the portion protruding to the lower right with respect to the horizontal will be aligned to the left end by correction, and it will not be possible to obtain an appropriate image, so in the case of a right turn, No correction was made for the portion protruding to the lower right.

With this, the inclination of the original can be detected simultaneously while reading the original. Therefore, in one reading process, the image data can be acquired, the black frame area can be removed, and the inclination direction of the original can be reduced with a very simple configuration. Can be detected.

(Embodiment 5) Next, an image processing apparatus according to Embodiment 5 of the present invention will be described. The image processing apparatus according to the fifth embodiment detects the removal of the black frame area, the inclination direction of the document, and the angle of the inclination in one reading operation.

FIG. 15 is a block diagram showing a schematic configuration of an image processing apparatus according to Embodiment 5 of the present invention. An M counter 1501 is a mask width detection counter at the left end,
The N counter 1502 is a rightmost mask width detection counter. Latch circuits 1503, 1505, 1507, 15
08 is a previous line latch circuit for comparing the previous line with the current line, and the comparators 1504 and 1506 compare the previous line with the current line.

Next, the operation of the image processing apparatus according to the fifth embodiment of the present invention configured as described above will be described. When a reading unit (not shown) starts reading a document, the read image data is input to the M counter 1501 and the N counter 1502. The functions of M counter 1501 and N counter 1502 are the same as in the first embodiment. The output of the M counter 1501 is input to the latch circuit 1503 for the previous line A, and the current line B is output to the comparator 1504
Is input to The comparator 1504 compares the value of the M counter 1501 in the previous line A with the value of the M counter 1501 in the current line B, and outputs the comparison result to the latch circuit 1507.

The output of the N counter 1502 is input to the latch circuit 1505 for the previous line A, and the current line B is input to the comparator 1506. Comparator 1506
Compares the value of the N counter 1502 in the previous line A with the value of the N counter 1502 in the current line B, and outputs the comparison result to the latch circuit 1508. Latch circuits 1507 and 1508 receive the instruction of the number of determination lines and output the change amounts of the M counter value and the N counter value. The tilt angle of the document is detected based on the output signals of these latch circuits 1507 and 1508. The detection of the inclination angle of the document will be described with reference to FIG.

FIG. 16 is a timing chart in the case where the image processing apparatus according to Embodiment 5 of the present invention detects the inclination angle of a document. In FIG. 16, the previous line is
The current line is assumed. The comparator 1504 calculates a difference A from the M counter value and the M counter value.
The comparator 1506 calculates a difference B from the N counter value and the N counter value. In the case of the original shown in FIG. 16, since A> B, the inclination direction of the original is determined to be “right”.

As shown in FIG. 16, the distance between the previous line and the current line is C, the angle formed by the left side of the document with respect to the horizontal is Δx, and the right side of the document with respect to the horizontal is The angle formed is Δy. In this case, Δx is calculated by the following equation. ∠x = tan ^-1 (C / A)

Next, the operation of the image processing apparatus according to Embodiment 5 of the present invention for detecting the inclination angle of the original will be described with reference to FIG.
This will be described with reference to FIG.

FIG. 17 is an operation flowchart for detecting the inclination angle of the document in the image processing apparatus according to the fifth embodiment of the present invention. When the reading of the document is started (step S1), it is determined whether or not a predetermined α line has passed (step S2). If it has not passed the α line, this determination is repeated, and if it has passed the α line, the first line count is instructed (step S3). As a result, the first M counter value and N counter value are determined. Next, it is determined whether the C line has elapsed (step S4). If the C line has not elapsed, this determination is repeated. If the C line has passed, the second line count is performed (step ST5). As a result, the second M counter value and the N counter value are determined. Thus, the values of A and B shown in FIG. 16 are determined. This value is stored in a memory (not shown).

Next, the values of A and B are read, and it is determined whether A is greater than B (step S7). A is B
If not larger, it is determined that the inclination of the document is left (step S8), and the angle is determined (step S8).
9). In this case, Δy shown in FIG. 16 is calculated by the following equation. ∠y = tan ^-1 (C / B)

On the other hand, if A is larger than B in step S7, it is determined that the original is tilted right (step S10), and the angle is determined (step S11). In this case, Δx shown in FIG. 16 is calculated by the following equation. ∠x = tan ^-1 (C / A)

Thus, instead of storing the entirety of the read image data in the memory once and detecting the inclination, the inclination of the original is detected at the same time as the original is being read. Accordingly, the four detections of image data capture, removal of the black frame area, the direction of inclination of the document, and its inclination angle can be performed in parallel.

[0081]

As is apparent from the above description, according to the present invention, the black pixel regions at both ends are simultaneously detected while outputting the image data of each line, and the black pixels at both ends of each image data are output. By outputting while disabling the pixel area, it is possible to automatically remove the black pixel areas at both ends from the image data in one reading process for the same line, so that the operator is not bothered.
Further, since the same document is not read a plurality of times, it is possible to realize appropriate removal of the black frame region of the image data without delaying the reading speed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of an image processing apparatus according to a first embodiment of the present invention;

FIG. 2 is a timing chart of an image reading operation and a writing operation in the image processing apparatus according to the first embodiment of the present invention;

FIG. 3 is a timing chart showing an input / output relationship of data when there is no black in one line of image data in the image processing apparatus according to Embodiment 1 of the present invention;

FIG. 4 is a timing chart showing a data input / output relationship when black is included in one line of image data in the image processing apparatus according to the first embodiment of the present invention;

FIG. 5 is a timing chart showing an input / output relationship of data when the first pixel of one line of image data is white in the image processing apparatus according to Embodiment 1 of the present invention;

FIG. 6 is a timing chart showing detection of a black area when input image data is halftone in the image processing apparatus according to the first embodiment of the present invention;

FIG. 7A is a diagram showing a state where a document is placed obliquely in the image processing apparatus according to the first embodiment of the present invention; Figure showing the case where the original is shifted from the range

FIG. 8 is a block diagram illustrating a schematic configuration of an image processing apparatus according to a second embodiment of the present invention;

FIG. 9 is a timing chart showing an input / output relationship of data in the image processing apparatus according to Embodiment 2 of the present invention;

FIG. 10A is a diagram illustrating a state where a document is placed obliquely in the image processing apparatus according to the second embodiment of the present invention; A diagram showing a range to be corrected and a range not to be corrected when the original is shifted left or right.

FIG. 11 is a block diagram illustrating a schematic configuration of an image processing apparatus according to a third embodiment of the present invention;

FIG. 12 is a timing chart showing an input / output relationship of data in the image processing apparatus according to Embodiment 2 of the present invention;

FIG. 13 is a block diagram illustrating a schematic configuration of an image processing apparatus according to Embodiment 4 of the present invention;

FIG. 14 is a timing chart in the case where the comparator detects a bending direction of a document in the image processing apparatus according to the fourth embodiment of the present invention;

FIG. 15 is a block diagram showing a schematic configuration of an image processing apparatus according to Embodiment 5 of the present invention.

FIG. 16 is a timing chart for detecting an inclination angle of a document in the image processing apparatus according to the fifth embodiment of the present invention;

FIG. 17 is an operation flowchart for detecting an inclination angle of a document in the image processing apparatus according to the fifth embodiment of the present invention;

[Explanation of symbols]

101 Line memory A 102 Line memory B 103, 1301, 1501 M counter 104, 1302, 1502 N counter 105 Mask M counter 106 Mask N counter 107 Mask unit 801 Mask generation unit 802 Enable generation unit 803 Tilt direction correction line detection unit 804 Selector 1001 line memory read address controller 1303, 1305, 1307, 1503, 1505,
1507, 1508 Latch Circuits 1304, 1306, 1308, 1309, 1504,
1506 Comparator 1310 Condition judgment unit

Continuation of front page (72) Inventor Akihiro Nagai 2-3-8 Shimomeguro, Meguro-ku, Tokyo Matsushita Electric Transmission System Co., Ltd. F-term (reference) 5C076 AA02 AA18 BA01 BA02 BA03 BA06 BA08 CA10

Claims (12)

[Claims] A storage unit for storing image data of a read document in line units; a first unit for detecting a continuous black pixel area from a reading start position of each line; Second means for resetting continuous black pixels appearing after the continuous black pixel area each time a white pixel appears, and detecting the last remaining continuous black pixel area; and the first means and the second means for each line. Means for obtaining valid image data by invalidating a continuous black pixel area corresponding to each line detected by the means of (2). 2. The method according to claim 1, wherein the first unit determines that the black pixels are continuous even when the white pixels are detected within a predetermined number, and the second unit detects the white pixels within a predetermined number. 2. The image processing apparatus according to claim 1, wherein it is determined that black pixels are continuous. 3. A first storage means for storing image data of a read document in units of lines, a first means for detecting a continuous black pixel area from a reading start position of each line, and the reading start on the same line. Second means for resetting continuous black pixels appearing after the continuous black pixel region from the position each time a white pixel appears, and detecting the last remaining continuous black pixel region;
Means for invalidating a continuous black pixel area corresponding to each line detected by the first means and the second means in each line to obtain effective image data of each line, and a second means for storing the effective image data The storage unit and, when writing each line to the second storage unit, control to change the write timing so that the start point of the effective area of each line after the second line matches the start point of the effective area of the first line. An image processing apparatus comprising: a control unit. 4. A storage means for holding image data of a read document in units of lines, a first means for detecting a continuous black pixel area from a reading start position of each line, and Second means for resetting continuous black pixels appearing after the continuous black pixel area each time a white pixel appears and detecting the last remaining continuous black pixel area; and in each line, the first means and the second means Means for obtaining valid image data by invalidating a continuous black pixel area corresponding to each line detected by the means of (2); and reading out image data of each line from the storage means. Control means for controlling the readout position so that the start point coincides with the start point of the effective area of the first line. 5. An image forming apparatus according to claim 1, further comprising: means for detecting whether the original is right-handed or left-handed. If the original is right-handed, said control means outputs one line for an area before the line where the start point of the effective image data is the leftmost end. Each line is written from the start point of the effective image data by shifting by an interval from the eye reading start position to the start point of the effective image data, while each line is written from the start point of the effective image data after the line at the leftmost end. 4. The image processing apparatus according to claim 3, wherein the timing is changed as described above. 6. A means for detecting whether a document is right-handed or left-handed, wherein said control means sets a line whose start point of effective image data is the leftmost line as a first line when the document is left-handed. The start point of the effective image data of each line is aligned with the start point of the effective image data of this line, while the timing is changed so that each line is written from the start point of the effective image data for the area before the line which is the leftmost end. The image processing apparatus according to claim 3, wherein: 7. A device for detecting whether a document is right-turned or left-turned, wherein said control means is configured to control, when the document is right-turned, one line for an area before a line whose effective image data start point is the leftmost end. Each line is read from the start point of the effective image data by shifting by an interval from the reading start position of the eye to the start point of the effective image data, while the area after the line at the leftmost end is read from the start point of the effective image data. The image processing apparatus according to claim 4, wherein each line is read. 8. A means for detecting whether a document is right-handed or left-handed, wherein the control means sets the first line of the effective image data as the first line when the document is left-handed. The start point of the effective image data of each line is aligned with the start point of the effective image data of this line, and reading of each line from the start point of the effective image data is performed for the region before the leftmost line. The image processing device according to claim 4. 9. A first means for detecting a first continuous black pixel area from a reading start position of each line, and a white pixel which appears after the continuous black pixel from the reading start position on the same line. A second means for resetting each time a pixel appears and detecting a last remaining second continuous black pixel area; a first difference of the first continuous black pixel area for a plurality of lines; Control means for calculating a second difference of the continuous black pixel area and determining whether the original is right-handed or left-handed based on the magnitude of the first difference and the second difference;
An image processing apparatus comprising: 10. A first means for detecting a first continuous black pixel area from a reading start position of each line, and a continuous black pixel appearing on and after the continuous black pixel from the reading start position on the same line. Second means for resetting each time a pixel appears and detecting the last remaining second continuous black pixel area;
For a plurality of lines, the first of the first continuous black pixel regions
And the second difference of the second continuous black pixel area are calculated, and it is determined whether the original is right-handed or left-handed based on the magnitude of the first difference and the second difference, and the first Control means for calculating a bending angle of the document based on the difference and the second difference. 11. A facsimile apparatus comprising the image processing device according to claim 1. 12. A step of holding image data of a read original in units of lines, detecting a continuous black pixel region from a reading start position, and appearing on the same line after the continuous black pixel region from the reading start position. Resetting a continuous black pixel every time a white pixel appears, detecting the last remaining continuous black pixel area, and invalidating the continuous black pixel area corresponding to each line to obtain valid image data. Image processing method provided.