JPH10341331A - Image processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the degradation of image quality in the case of arbitrary angle rotation by reading an original, while enlarging an image at the time of image read according to a reading scale factor calculated based on an inclined angle detected by an inclination detecting means. SOLUTION: First, a reader reads an original through the prescan of original and detects the inclined angle of original. Corresponding to the inclined angle, a memory unit part 30 calculates the image reading scale factor. Next, an image signal processing part 20 reads the original, while enlarging it according to the scale factor in the case of main scan of original. Afterwards, the memory unit part 30 corrects the inclination of image quality according to the inclined angle of the read image signal. The obtained image is an image in normal direction. In this case, when a user sets the desired copying scale factor, the image reading scale factor is calculated from the copying scale factor and the detected inclined angle. Thus, after an arbitrary angle rotating processing, the image becomes a corrected image in the normal direction with the desired copying scale factor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a digital copying machine,
The present invention relates to an image reading apparatus used for an image forming apparatus such as a facsimile, a multifunction peripheral, and the like.

[0002]

2. Description of the Related Art When a document placed on a document glass for reading a document image is erroneously tilted, it is desirable to correct the tilt of the document. For this reason, an arbitrary angle rotation processing function of two-dimensional image data to be output from the image reading device has been proposed (for example, Japanese Patent Publication No. 63-63).
No. 9266). In the arbitrary angle rotation processing, the inclination of the original placed on the original glass is detected, the image data is rotated in a normal direction, and an image is formed using the corrected image data. As a result, a document placed by the user inadvertently tilted can be automatically corrected in image tilt and output.

[0003]

In one method of the inclination correction processing by the arbitrary angle rotation, rotation processing is performed by combining image data shift processing and 90 ° rotation in two scanning directions. In this case, in order to keep the size of the original image unchanged, the electrical scaling process is performed after the shift process in each scanning direction. However, in this case, since it is necessary to perform the electric scaling process for each shift process, a line is inserted by the electric scaling process, and the image quality is deteriorated. Therefore, a good corrected image cannot be obtained.
Further, a long processing time is required for the rotation processing.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus in which image quality is hardly deteriorated when rotating at an arbitrary angle.

[0005]

An image processing apparatus according to the present invention comprises: an inclination detecting means for detecting an inclination angle of a document placed on a document glass; and an inclination angle detected by the inclination detecting means. Magnification calculating means for calculating a magnification of image reading, image reading means for converting a document into an image signal according to the magnification calculated by the magnification calculating means and outputting the image signal, and an image signal read by the image reading means And a tilt correcting means for correcting the tilt of the image according to the tilt angle detected by the tilt detecting means. Thus, according to the reading magnification calculated by the magnification calculating means in accordance with the inclination angle detected by the inclination detecting means, the image is enlarged and the original is read at the time of image reading. In the tilt correction, the image is returned to the original image size and corrected in a normal direction. As a result, a normal image signal is output. Thus, the deterioration of the image quality in the inclination angle correction is reduced, and the corrected image is generated at high speed. Preferably, the magnification is a magnification for reading an image in the sub-scanning direction. In this way, when reading the image, the original is read by enlarging the image in the sub-scanning direction. Therefore, in the shift shift process in which the scaling and the 90 ° rotation are performed in each scanning direction, the electric scaling process in the sub-scanning direction becomes unnecessary. An increase in processing time due to the electric scaling process and deterioration in image quality due to insertion of a line in the electric scaling process are eliminated. Preferably, the apparatus further comprises a magnification setting means for setting a desired magnification, wherein the magnification calculation means performs image reading based on the inclination angle detected by the inclination detection means and the magnification set by the magnification setting means. Calculate the magnification. Thus, after the image rotation, an image signal having the magnification set by the magnification setting means is output.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A digital copying machine as an embodiment of the image forming apparatus of the present invention will be described below with reference to the accompanying drawings. (1) Configuration of Copying Machine FIG. 1 schematically shows the overall configuration of a digital copying machine 1. The digital copying machine 1 includes a reading device 200, a printer device 300, a document transport unit 500, an operation panel (see FIG. 2), and a re-feed unit 600. The document transport unit 500 automatically transports the document set on the document feed tray 510 to a reading position on the document glass 18 and, after the reading device 200 reads the document, discharges the document to the discharge tray 5.
Discharge to 11 The size of the original is determined by sensors 551 and 55
2 detected. The reading device 200 includes a scanning system, the image processing unit 20, and the like. In the scanning system, the original glass 18
The upper document is read, and image data corresponding to each pixel of the image of the document is generated. That is, the original is irradiated by the exposure lamp 12 attached to the scanner 19 that moves below the original glass 18. Light reflected from the document passes through a first mirror 12, fixed mirrors 13a and 13b, and a condenser lens 14, and is incident on a line sensor (photoelectric conversion element) 16 using a CCD array or the like. The scanner position sensor 17 is provided to detect that the scanner 19 reaches the document reading area (image area). The line sensor 16 has a large number of photoelectric conversion elements arranged in a direction (main scanning direction) orthogonal to the paper surface of FIG. 1. The line sensor 16 reads an image at 400 DPI, for example, and outputs reflected light corresponding to each pixel of the image of the document. The signal is converted into an electric signal and output to the image signal processing unit 20. The image signal processing unit 20 processes the input electric signal and outputs image data to the memory unit 30. Here, the image signal processing unit 20 can detect the inclination of the document. The memory unit section 30 compresses and temporarily stores the image data input from the image signal processing section 20, and then performs decompression processing and transmits it to the printer device 300. At the time of decompression, if necessary, editing processing such as rotation of the inclined document by an arbitrary angle is performed. Further, the memory unit section 30 includes an external device interface section described later, and is connected to an external device through an external cable 51 via an external device connection connector 50.

The printer device 300 includes a print processing unit 40,
It comprises a laser optical system 60, an image forming system and the like. The print processing unit 40 controls the laser optical system 60 based on the image data received from the memory unit 30. In the laser optical system 60, the semiconductor laser 61 emits a laser beam modulated by a signal from the print processing unit 40, and the polygon mirror 65 deflects the laser beam and scans the laser beam on the photosensitive drum 71. That is, the deflected laser beam is guided to the exposure position on the photosensitive drum 71 via the f-θ lens 66 and the reflection mirrors 67 and 68, and the scanning of the original image on the photosensitive drum 71 is performed by this scanning. An image is formed.

Image formation is performed by an electrophotographic method in an image forming system, and a latent image formed on a photosensitive drum 71 is developed, transferred and fixed on paper to form an image on paper. Here, the photosensitive drum 71 rotated and driven in the counterclockwise direction in FIG. 1 is uniformly charged by the charging charger 72 and then exposed, and the latent image is developed by the developing unit 73.
(Only one developing device is shown for simplicity of illustration, but a color image can be developed by providing developing devices for four colors of cyan, magenta, yellow, and black.) Then, the toner image is guided from the cassettes 80a and 80b to the photosensitive drum 71 through the sheet guide 81 and the timing roller 82, and the toner image obtained by the development is transferred to the sheet by the transfer charger 74. Next, the sheet is separated by the separation charger 75 and is conveyed to the fixing roller 84. The fixing roller 84 fixes the image on the sheet by heat, and then the sheet is discharged through the re-feed unit 600.

FIG. 2 is a plan view of the operation panel of the copying machine. The operation panel includes a liquid crystal touch panel 91 for status display and various mode settings, a numeric keypad 92 for inputting numerical values (number of sheets, magnification, etc.), a clear key 93 for returning numerical values to standard values, and a copy mode. Panel reset key 94 for initializing, stop key 95 for instructing stop of copy, start key 96 for instructing start of copy, interrupt key 97 for designating interrupt start and return, tilt angle correction A key 102 for instructing a mode is arranged. By pressing the key 102, various choice settings (mode setting, etc.) related to the arbitrary angle rotation function can be made on the liquid crystal touch panel 91.
Can be performed. FIG. 3 shows an example of a system configuration in which a plurality of digital copying machines 1, 1 'are connected on a network. The digital copying machines 1 and 1 'are connected to controllers 2 and 2', which are an example of external equipment, via an external equipment interface connector 50 and an interface cable 51. The controller 2 is connected to the computer 3 via a general-purpose interface such as Ethernet, and is connected to another digital copying machine 1 'through the controller 2'. As an example, when various settings (conditions such as paper size, magnification, number of prints, staple, sorting, etc.) and an output command are input for printing a data file created by the computer 3, print processing on the computer 3 is performed. Is sent to the controller 2. The controller 2 generally converts image data (such as PostScript data) sent from the computer 3 into raster data. Therefore, the controller 2 is equipped with a memory for at least one screen. When converted into bitmap data, the image data is transmitted to the digital copying machine 1 (at the same time, various setting conditions are also transmitted via the controller 2). Processing is performed. It should be noted that the present invention is not limited to this system form, but also includes a system such as a facsimile apparatus connected to a modem through a telephone line.

(2) Copying Machine Control System FIGS. 4 and 5 show a control unit 100 for controlling the copying machine 1. The control unit 100 is mainly composed of eight CPUs 101 to 107. Each of the CPUs 101 to 107 has a ROM 111 to 117 storing a program and a RAM 121 to 117 serving as a work area for executing the program.
127 are provided. Note that the CPU 103 is provided in the memory unit 30.

The first CPU 101 controls input of signals from various operation keys on an operation panel (see FIG. 2) and display on a liquid crystal touch panel. The second CPU 102 controls driving of a scanning system of the reading device 200 and controls each unit of the image signal processing unit 20. Here, the inclination of the document is detected from the read image. The third CPU 103 compresses the read image data by controlling the memory unit 30, temporarily stores the read image data in the code memory 303, then reads out the image data and outputs it to the print processing unit 40. Here, at the time of reading, rotation editing of image data including image tilt correction is performed. The memory unit 30 has a function of interfacing with an external device, and transmits and receives image data and control data. The fourth CPU 104 controls the print processing unit 40, the optical system 60, and the image forming system of the printer device 300. The fifth CPU 105 controls the control unit 10
Processing for adjusting the overall timing of 0 and setting the operation mode is performed. The sixth CPU 106 controls the document conveying unit 50
0 is controlled. The seventh CPU 107 controls the sheet re-feed unit 600. These CPUs 101 to 10
Between 7, serial communication is performed by interruption, and commands, reports, and data are transmitted and received.

FIG. 6 is a block diagram of the controller 2 controlled by the CPU 105. The first external interface 700 exchanges signals with the external computer 3. The interpreter 702 translates data (for example, postscript data) sent from the computer 3 and develops the data into raster data,
2 stores raster data. When one page of image data is stored, the image data is output to the printing unit via the second external interface 704.

Next, processing of image data will be described. FIG. 7 illustrates an image signal processing unit 20. The image signal processing unit 20 includes a timing control unit 21, an amplifier 23, an A / D
Converter 25, shading correction unit 26, density conversion unit 2
7, an electric scaling section 28, an editing section 29, etc.
It is controlled by the PU 102. The image signal processing unit 20 converts the input signal from the line sensor 16 into an amplifier 23
And amplified by the A / D converter 25 for each pixel.
It is quantized to bit image data. The image data is then subjected to various processes such as shading correction, conversion to density data (gamma correction), electric scaling, and editing, and then sent as image data to the memory unit 30 or a printer device. The CPU 102 controls the image signal processing unit 20
Of the scanner unit of the laser scanning system, communication with the CPU 105, and the like, and controls the entire reading apparatus 200. The document size and the orientation of the document are detected as follows. In determining whether or not the read image is a document, for example, the document placed on the document glass 18 is scanned by setting the document cover of the document feeder 500 to a mirror-like surface, and a portion where the amount of reflected light is large is determined as the document. to decide. If the mirror surface is used, the amount of reflected light is very small, so that the determination is easy. Therefore, scanning may be performed with the document cover opened. C
When receiving an instruction of the document size detection operation from the CPU 105, the PU 102 performs a preliminary scan. CPU10
2 controls a scanner motor that drives the scanner 19 based on position information from the scanner position sensor 17;
The scanner 19 is caused to scan in the sub-scanning direction. At the timing corresponding to the sub-scanning position, the document size and the portrait / landscape orientation are detected from the content of the image data and the monitor position information, and the detection result is transmitted to the CPU 105. The CPU 102
Based on the magnification information transmitted from the PU 105, at the time of image reading, the speed of the scanner motor is controlled at a scan speed that matches the magnification information.

FIG. 8 is a block diagram of the memory unit 30. The switching unit 301 switches the route of image data to the image signal processing unit 20, the print processing unit, and the external interface 310. The area determining unit 303 determines whether the input image data is simple binary data or halftone data. The binarization processing unit 302
Based on the parameter settings from the CPU 103, the image data is converted into binary data within a range that can be restored to multi-valued image data by error diffusion, dithering, or the like. The image memory has a capacity for two pages. The binary data is stored in the image memory. The binary data read from the image memory 304 is then sent to the compressor 3 in the code processing unit 305.
11 and stored in the code memory 306. The code memory 306 stores, for example, A at 400 DPI.
This is a multi-port memory having a capacity of one page of four sizes. The code memory 306 temporarily stores read data of a document image of a plurality of pages. The data in the code memory 306 is managed by a code management table provided in the RAM 126.

At the time of printing, the compressed image data in the code memory 306 is expanded by an expander 312. If image editing is required, the editing control unit 307 performs editing processing (rotation, scaling, movement, etc.) at the time of decompression, and performs the editing processing and decompression processing simultaneously. If necessary, a tilt angle rotation is also performed at the time of extension. The decompressed data is transferred to the image memory 304. When the data of one page is decompressed, the binary data read from the image memory 304 is converted into multi-value data by the multi-value processing unit 308.
If necessary, after the smoothing processing is performed in the smoothing processing unit 309, the data is transferred to the print processing unit 40 or the external device via the switching unit 301. CPU103
Sends control parameters to the multi-value processing section 302 and the smoothing processing section 309.

Next, the operation sequence of the copying machine 1 in image reading and printing will be described with reference to the CPUs 101 to 106.
Command (Q), report (A) exchanged between
And the flow of data. FIG. 9 shows a schematic sequence of the memory write operation. First, the fifth CPU 105, which manages the entire sequence, requests the third CPU 103, which controls the memory unit 30, to prepare for memory. In response, the CPU 103
Setting of a bus connection state for transferring image data from the image signal processing unit 20 to the image memory 304 to the internal hardware, setting of a mode for binarization processing, start address of a writing area in the image memory 304 , X
Make settings such as Y-length information. When these settings are completed and the preparation is completed, the CPU 103
05 is notified of the completion of memory preparation. Next, CP
U105 requests the CPU 103 and CPU 102 to read. In response, the CPU 102 requests the document scanning unit of the reading device 200 to scan. In this way, when the scanning of the original is started and the scanner 19 reaches the original reading area on the original glass, the read data is read according to the image processing mode set by the CPU 102.
(Image data D2) is transferred from the image signal processing unit 20 to the memory unit unit 30. When the scan is completed, a scan end signal is sent to the CPU 102, and the CPU 102
103 notifies the CPU 105 of the completion of the reading. Next, the CPU 105 requests the CPU 103 to compress the data. In response to this, the CPU 103 sets the read address from the image memory 304, the XY length information, the write address to the code memory 306,
Eleven modes (for example, arithmetic coding system and MH system) are set, and each unit is started. This allows the compressor 3
11 is performed, and the code data is stored in the code memory 306. When the compression process is completed, the CPU 1
03 notifies the CPU 105 of the completion of compression. At this time, if the code memory 306 is full of data, a compression completion report to which a parameter indicating that compression is impossible is added is sent to the CPU 105. Thus, the CPU 105 can know that the code memory 306 has become full.

FIG. 10 shows a schematic sequence of a memory read operation. In the memory read operation, image data is read from the image memory 304, and a copy image is printed on a sheet based on the image data. CPU10
5 requests the CPU 103 to decompress data. In response, the CPU 103 reads the address from the code memory 306, the amount of data, the write address to the image memory 304, the XY length information, the mode of the decompressor 312 (for example, the arithmetic coding method and the MH method), Set the edit processing mode such as angular rotation and start each unit. As a result, decompression (editing) processing is performed, and the image data is written to the image memory 304.
When the decompression process is completed, the CPU 103 notifies the CPU 105 of the completion of the decompression. Next, the CPU 105
The PU 103 is requested to prepare a memory for reading an image from the image memory 304. In response, CP
U103 is the image memory 3 for the internal hardware.
04, the setting of the bus connection state for outputting the image data to the print processing unit 40, the setting of the start address of the read area of the image memory 304, the XY length information, and the like are performed, and the CPU 105 is notified of the completion of the memory preparation. next,
The CPU 105 controls the CPU 103 and the printing unit 40
Request a print. From the print processing unit 40 to the CPU 105
Then, a paper feed report notifying the paper transport state is sent to the printer, and thereafter, the image data read from the image memory 304 is output to the print processing unit 40, and printing is performed. When printing is completed, the CPU 103 and the print processing unit 40
A print completion report and an ejection completion report are sent to the PU 105. C who received these reports
The PU 105 gives a memory clear request to the CPU 103 as needed.

(3) Document Reading When Document is Tilt Next, image reading when the document read on the document glass 18 is tilted will be described. As shown in FIG. 11, the document 10 is placed with its copy surface facing downward on a document glass 18 with reference to the upper right end (indicated by a triangle). The longitudinal direction of the original glass 18 is the sub-scanning direction of scan reading, and the direction perpendicular thereto is the main scanning direction. In the example shown in FIG. 11, the document is placed away from the image reference, and its position is not parallel to the sub-scanning direction. In this example, the document does not protrude from the reading area. FIGS. 12 and 13 show images of a read image when the document 10 (shown by a broken line) does not protrude from a reading area (a rectangle shown by a solid line). (Since the document 10 is viewed from the copy surface side, the image reference is at the upper left corner.) The image signal processing unit 20 processes image data of a rectangular area including at least the range of the document and processes the image data of the document area where the document exists. Perform detection,
From all the coordinates around the original (that is, the edge),
As shown in the figure, the coordinates of the four corners of the rectangular document are detected. Here, the main scanning direction is the X axis, and the sub scanning direction is the Y axis. X _max and X _min are the maximum and minimum X coordinates. Of the remaining two X coordinates, the larger _one is X ₁ and the smaller _one is X ₂ . Y _max and Y _min are the maximum and minimum Y coordinates. Of the remaining two Y coordinates, the larger _one is Y ₁ and the smaller _one is Y ₂ . In the example of FIG. 12, the X and Y coordinates of the four corners of the document are (X ₁ , Y _min ),
(X _max, Y _2), a _{(X min, Y 1),} (X 2, Y max). The lengths a, b, c, and d of the four sides of the document 10 can be calculated as follows from the coordinates of the document. a = {(X _max −X ₁ ) ² + (Y ₂ −Y _min ) ² } b = {(X ₁ −X _min ) ² + (Y ₁ −Y _min ) ² } (1) c = √ {(X ₂ −X _min ) ² + (Y _max −Y ₁ ) ² } d = {(X _max −X ₂ ) ² + (Y _max −Y ₂ ) ² } In the example of FIG. Unlike the case of FIG. 12, the coordinates of the four edges of the document are (X _min , Y ₁ ),
(X ₁ , Y _min ), (X ₂ , Y _max ) and (X _max , Y ₂ ). Also in this case, the lengths a, b, c, and d of the four sides can be calculated by the same formula. Here, the editing processing parameters for correcting the tilted image are as follows. First, X ₁ −X _min <
In the case of Y ₁ −Y _min (FIG. 12), rotation coordinates: (X ₁ , Y _min ) Rotation angle θ: tan ⁻¹ {(X ₁ −X _min ) / (Y ₁ −Y _min )} (2) Destination Nation address (pmmax, pmday): (−X ₁ , −Y _min ) When X ₁ −X _min > Y ₁ −Y _min (FIG. 13), rotation coordinates: (X _min , Y ₁ ) Rotation angle θ : Tan ^-1 {(Y ₁ −Y _min ) / (X ₁ −X _min )} (3) Destination address (pmdx, pmday): (−X _min , −Y ₁ ) The rotation coordinates are the upper left corner of the figure. Are the coordinates of the corner near. The rotation angle θ is a rotation angle for rotating the original with reference to the rotational coordinate position to make the original parallel to the reading area. The destination address is the coordinates of the transfer destination to the memory, and corresponds to the length from the upper left position to the image reference.

When the original 10 is out of the reading area (solid line rectangular portion), for example, even if the read image (broken line) is an image as shown in FIG. 14, the above coordinates are detected by detecting the original area. I do. The upper left end of the figure is the reference position of the reading area. Now, the reading range of the X axis is X _min0 ~
It is assumed that X _max0 and the reading range of the Y axis is Y _min0 to Y _max0 . Since the corner of the document is outside the reading area, the extreme value X
Each of _max , X _min , Y _max , and Y _min is detected at two points that intersect the edge of the reading area. That is, when the extreme values of the X axis and the Y axis match the maximum values X _max0 , Y _max0 or the minimum values X _min0 , Y _{min0 of the} reading range, two points are detected. Thus, the coordinates of the eight points at the edge of the document are (X _min0 , Y
_{10), (X min0, Y} 11), (X 10, Y min0), (X 11,
_{Y min0), (X 20,} Y max0), (X 21, Y max0), (X
_max0, Y _20), a (X _max0, Y _21). Thus, sides a, b, c, and d existing in the reading range can be extracted. Here, the lengths a, b, c, and d of the four sides of the document and the lengths e, f, g, and h of the protruding portion can be calculated from these coordinates as follows. a = √ ｛(X _max0 −X ₁₁ ) ² + (Y ₂₀ −Y _min0 ) ² ｝ b = √ ｛(X ₁₀ −X _min0 ) ² + (Y ₁₀ −Y _min0 ) ² ｃ c = √ ｛(X ₂₀ −X _min0 ) ² + (Y _max0 −Y ₁₁ ) ² ｝ d = √ ｛(X _max0 −X ₂₁ ) ² + (Y _max0 −Y ₂₁ ) ² ｝ (4) e = X ₁₁ −X ₁₀ f = Y ₁₁ −Y ₁₀ g = X ₂₁ −X ₂₀ h = Y ₂₁ −Y _{20 Further} , as shown in the figure, the lengths of the four sides when the document is rectangular can be calculated as follows. e * cosθ + a + h * sinθ, f * cosθ + b + e * sinθ, (5) g * cosθ + c + f * sinθ, h * cosθ + d + g * sinθ. Here, the inclination angle θ can be calculated for each side from the coordinates described above.

On the basis of the above-described concept, it is possible to obtain the editing processing parameters corresponding to every manner of placing the original. If at least one of the four sides can be extracted, the inclination angle θ can be calculated. In addition, the length and coordinates of each side can be calculated when the extracted side is regarded as a part of the side and the rectangular area including the read original area is defined as the effective original area.

(4) Correction of Tilt Angle by Arbitrary Angle Rotation When the tilt of the read document is detected, the image is automatically rotated by the tilt angle to obtain an image that does not tilt. Therefore, when the user places the document on the document glass and erroneously places the document on the document glass, the image is automatically rotated by the tilt angle, so that a normal image can be obtained. In the arbitrary angle rotation processing, first, the original is read by prescanning the original, and the inclination angle of the original is detected. Then, the magnification of the image reading is calculated in accordance with the tilt angle. Next, in the actual scan of the original, the original is enlarged and read according to the magnification. Next, the inclination of the image is corrected according to the inclination angle with respect to the image signal thus read. The obtained image is an image in a normal orientation. When the user sets a desired copy magnification, the image reading magnification is calculated from the copy magnification and the detected inclination angle. Thus, the image after the arbitrary angle rotation processing is a corrected image in a normal direction at a desired copy magnification. In the arbitrary angle rotation processing according to the present embodiment, rotation processing is performed by combining image data shift processing and 90 ° rotation in two scanning directions (Equation 2).
(8)). In this case, in order to keep the size of the original image unchanged, scaling processing (enlargement and reduction) is required after the shift processing in each scanning direction. If an electric scaling process is used in this scaling process, the image quality will be degraded due to the insertion of lines by the electrical scaling process, and the processing time required for the rotation process will be long. Therefore, the reading magnification is calculated according to the detected inclination angle, and the image is optically enlarged in the sub-scanning direction when reading the image, and the original is read. As a result, the number of times of the electric scaling process is reduced from two to one, so that the image quality deterioration and the increase in the processing time due to the electric scaling process are reduced.

Hereinafter, the arbitrary angle rotation processing will be described in more detail. The arbitrary angle rotation is performed based on the editing parameters detected by the image reading.
In the editing processing unit 307. First, the editing processing unit 307 will be described. FIG. 15 shows a portion related to the arbitrary angle rotation of the edit processing unit 307 in the memory unit 30 and the image memory 304. Editing such as rotation by the editing processing unit 307 is performed by using the image memory 304 and combining shift processing, XY conversion processing, and bit swap processing (see FIGS. 16 and 17). When the rotation processing is not performed (0 ° rotation), only the bit swap processing is performed as shown by the broken line, and the signal W2,
Only R2 is accessed. In the case of performing the rotation processing, the input image data transferred from the decompression unit 312 is 16 bits, and is converted into 32 bits by the 16 → 32 conversion unit 3070 in the editing processing unit 307 first. Editing unit 3
In order to process the internal operation of 07 and access to the image memory 304 at high speed, all data processing is performed in 32 bits. The first shift unit 3071 performs a shift process if the data after the bit conversion is necessary, and
4 are written to the 1-1 slice area unit 3040 and the 1-2 slice area unit 3041. The 1-1X-Y conversion section 3072 and the 1-2X-Y conversion section 3073 respectively
For data R1 read from the 1-1 slice area unit 3040 and the 1-2 slice area unit 3041, X
-Perform Y conversion processing. The second shift unit 3074 performs a shift process on the data after the XY conversion, if necessary. The first bit swap unit 3075 includes a 16 → 32 conversion unit 30
If necessary, the data from the memory 70 or the data from the second shift unit 3074 is subjected to bit swap processing, and is written into the virtual paper area 3042 for editing in the image memory 304 (capacity of A3 size at maximum). Second XY converter 30
Reference numeral 76 denotes R2 read from the virtual paper area 3042 for print output in the image memory 304 by the second bit swap unit 3077 if necessary at the time of print output.
The data is subjected to XY conversion processing and written to the second slice area 3043 in the image memory 304. R2 read from virtual paper area 3042 during print output operation
The data or the R3 data read from the second slice area 3043 is converted into one bit by the 32 → 1 conversion unit 3078 and transferred to the multi-value processing unit 308. During continuous operation, access to the image memory 304 (signal W
1 to W3, R1 to R3) are processed in parallel on a 32-bit bus line in a time division manner.

Next, referring to FIG.
The 0 ° rotation processing will be described. The image of the input image transferred from the decompression unit 312 is received with the upper left end as the image reference, as shown in FIG. The input image data is, as shown in (b) at the upper right, the first to the first in the line unit.
The data is read from the slice area unit 3040 in units of 32 bits × 32 bits from data of 32 bits × 32 lines, and is edited by the 1-1X-Y conversion unit 3072. Next, for 90 ° rotation, the center (c)
Is read out as shown in FIG.
The data is written in the virtual paper area 3042. At this time, image reference (destination address (pmdax, pmday))
Expand the data so that is at the lower left. 1-1 slice area section 3040 and 1-2 slice area section 3
No. 041 is a pair, and the above processing is performed by a double buffer operation. Next, referring to FIG. 17, first bit swap unit 3075 and second bit swap unit 3077
A bit swap process of image data according to will be described. In this process, as shown in the upper part of the figure, the arrangement of the 32-bit data is reversed. Then, as shown in the lower part of the figure, the inverted data is written in the virtual paper area 3042 such that the image reference (destination address) is at the lower right corner. In addition, by combining the 90 ° rotation and the bit swap processing, it is also possible to rotate 270 °. At this time, the data is developed so that the image reference is at the upper right end. The editing processing unit 307 can simultaneously process the parallel movement of the image by changing the transfer destination (destination address) to the virtual paper area based on the image. Although not described, processing such as erasing, copying, and pasting of an image in a specific area is also possible.

Next, a description will be given of a rotation address calculation for an arbitrary angle rotation. The following equation shows a rotation process in the affine transformation. As shown in Expression (6), the coordinates (X, Y) are rotated by the angle θ to become coordinates (U, V). This operation is usually decomposed as shown in Expression (7), and is a combination of the first shift, scaling (enlargement), 90 ° rotation, scaling (reduction), second shift, and -90 ° rotation. .
The above-described editing processing unit 307 performs an operation by combining these processes. In the first shift and the second shift, Y
Only the X-axis parameters are processed with the axis parameters fixed.

(Equation 1)

Equations (6) and (8) show the processing when the variable magnification processing in the sub-scanning direction is performed at the time of reading. Equation (8) shows decomposition when performing scaling processing in the sub-scanning direction. The rotation address calculation includes scaling (enlargement), first shift, 90 ° rotation, second shift, scaling (reduction), -90 °
It becomes a combination of rotation. Equation (8) differs from Equation (7) in the order of the first shift and the scaling (enlargement) processing.

(Equation 2)

In the arbitrary angle rotation processing of the image data, the image data is processed according to the above-described calculation for the arbitrary angle rotation. The arbitrary angle rotation processing (shift shift method) of image data will be described with reference to FIG. In the editing processing unit 307, as shown in the upper left of FIG. 22, the image of the input image transferred from the decompression unit 312 is received on the basis of the upper left corner. The input image data is subjected to a first shift process in the above-described first shift unit 3071 in accordance with the set rotation angle θ, as shown in the upper part of the center of FIG.
1 slice area 3041 and 1-2 slice area 3
042 is written in line units. Next, a 1-1 slice area 3041 and a 1-2 slice area 304
The data is read out in units of 2 to 32 × 32 bit blocks, and processed by the 1-1X-Y conversion unit 3072 and the 1-2X-Y conversion unit 3073. Next, based on the data for the two blocks, the second shift unit 3074 performs a second shift process according to the set rotation angle θ, and writes the data to the virtual paper area 3042. The two slice areas 3040 and 3041 form a pair, and the above operation is performed by a double buffer operation. With the processing so far, the image is rotated by (90 ° + θ). When printing out from the virtual paper area 3042, -90
The rotation by 270 ° (270 ° rotation) is processed using the second XY conversion unit 3076 and the second bit swap unit 3077, buffered (bit converted) to the second slice area unit 3043, and then multi-valued. Output to the unit 308. In the rotation process by the shift method, θ is desirably as small as possible in consideration of the image quality after the process.
<Θ <45 °. 90 ° rotation for more angles
Process by combining with unit rotation.

FIG. 19 and FIG. 20 are diagrams schematically showing a state where the normal rotation address calculation using the above-described arbitrary angle rotation processing (shift shift processing) is performed from the right side of the equation (7). . First, the image data of the reading area is the first
A first shift process is performed according to the rotation angle set in the shift unit. Thereafter, an electric scaling process (enlargement) is performed in order to match the data after the rotation process with the size of the input image data. Then, in order to process the next shift process in the X direction, a process of -90 ° rotation is performed. Next, in order to adjust the data after the rotation process to the size of the input image data, an electric scaling process (reduction) is performed. Is performed. Next, a second shift process is performed. Since the image data has been rotated by (90 + θ) ° by the processing so far, it is rotated by 90 ° and returned to the state rotated by θ °.

FIGS. 21 and 22 show the case where the rotation address calculation for changing the magnification in the sub-scanning direction using the above-described arbitrary angle rotation processing (shift shift processing) is performed from the right side of equation (8). Is a diagrammatic representation of the situation. First, the image data in the reading area is enlarged by cos ⁻¹ θ times in the Y direction by a sub-scanning magnification process during reading in order to match the data after the rotation process with the size of the input image data. next,
The first shift unit according to the rotation angle set in the first shift unit
Shift processing is performed. Then, in order to process the next shift process in the X direction, a process of -90 ° rotation is performed.
Next, in order to adjust the data after the rotation processing to the size of the input image data, an electric scaling process (reduction) is performed. Next, a second shift process is performed. Since the image data has been rotated by (90 + θ) ° by the processing so far, it is rotated by 90 ° and returned to the state rotated by θ °.

(5) Control of Copying Machine The control flow of the copying machine will be described below. FIG.
5 is a main flowchart of a first CPU 101 that controls an operation panel. When the power is turned on, first, an initialization for initializing a RAM, a register, and the like is performed (step S11). Thereafter, an internal timer that defines the length of one routine is set (step S12), key input processing for accepting key operation is performed (step S13), and panel display processing for performing display according to the key operation is performed (step S14). ). Then, a choice setting process is performed for the tilt angle rotation process (step S15). Further, after performing other processing (step S16), the process waits for the end of the internal timer (YES in step S17), returns to step S12, and repeats the above processing. In addition, communication with another CPU is performed as interrupt processing at an appropriate time.

FIGS. 24 and 25 are main flowcharts of the second CPU 102 for controlling the image signal processing section 20. After the initial setting for initializing the RAM and the registers is performed (step S21), an internal timer that defines the length of one routine is set (step S22). Next, image reading control is performed. When the scan is started (YES in step S23), it is determined whether or not a pre-scan is performed (step S24). If it is a pre-scan, the sub-scanning magnification is set to 1 (step S25), image data is input (step S26), and a document is detected (step S27, see FIG. 26). And the tilt angle θ
Is calculated as the sub-scanning magnification (step S28). Then, other processing is performed (step S2).
9) Next, wait for the end of the internal timer (step S).
2A), returns to step S22, and repeats the above processing. Also, if it is not pre-scan,
In the case of the main scan, in FIG. 25, first, the sub-scanning magnification calculated in step S28 is set (step S2).
B, see FIG. 36) and input image data (step S2).
C), a document is detected (Step S2D), image processing is performed (Step S2E), and data is output (Step S2).
2F). Then, other processing is performed (step S2).
9) Next, wait for the end of the internal timer (step S).
2A), returns to step S22, and repeats the above processing.

FIG. 26 is a flowchart of the document detection process (FIG. 24, step S27, FIG. 25, step S2D). First, sides and coordinates are extracted from the data of the document image, and a protrusion from the reading area of the document is detected (step S251). Further, angle detection (step S252,
27 to 28), size detection (step S25)
3, see FIGS. 29 to 31), size setting (step S2)
54, refer to FIG. 32), setting the rotation coordinates (step S25)
5, see FIG. 33), destination setting (step S256, see FIG. 34), 90 ° rotation destination setting (step S257, see FIG. 35), and other processing (step S258). (In the case of pre-scan, steps S254 to S25
7 is not performed. In this process, even if the document is placed outside the reading area, the area where the document exists (document area) is detected from the image data, and each side is extracted from the coordinates of the detected document area to form a rectangle. And the four corners of the document are estimated. Next, various parameters for the arbitrary angle rotation are determined. The parameters include: The tilt angle (rotation angle) θ (see step S252) represents the tilt of the effective document area. Effective document area size spx, spy
(See step S253) is a parameter representing the size of the detected document (x direction and y direction when the document is not inclined). In addition, size cpx, cpy
Is a size parameter (x direction and y direction) for setting a virtual paper area for developing image data. The paper size (see step S254) is usually the minimum standard paper size including the effective document area. Rotation coordinates rot
_x and rot_y (see step S255) represent coordinates (x direction and y direction) that are the rotation center with respect to the origin of the reading area. For example, in the example of FIG. 14, since the upper left corner is the origin of the reading area, the rotation coordinates rot_x, ro
t_y represents the corner of the upper left effective document area 10 (represented by a broken line) closest to the origin, and is an amount representing the displacement of the document. The destinations (shift amounts) pmmax and pmday (refer to step S256) represent the coordinates with respect to the origin of the virtual paper area from the rotational coordinates. When the image data is developed in the virtual paper area, the coordinates are moved by the destination only. The image data is developed from the origin of the virtual paper area. The 90 ° rotation parameter (see step S257) is a parameter used when rotating an image by 90 °. The various parameters obtained are set in editing control for the image memory (see FIG. 38).

FIG. 27 shows the angle detection (FIG. 26, step S).
It is a flowchart of 252). First, angles θ _a , θ _b , θ _c , θ _d are obtained from the sides a, b, c, d of the document area, respectively.
Is detected (step S2521, see FIG. 28). When the angle detection is completed, the angle used for the actual rotation processing is selected. If all the angles θ _a , θ _b , θ _c , θ _d are incorrect (YES in step S2522), or
If it is not θ _a ≒ θ _b ≒ θ _c ≒ θ _d (excluding an incorrect angle) (NO in step S2525), that is, if there is an angle detected from the four sides that is significantly different from the others,
In other words, if it is not a rectangle, size_err is set to 1 and the arbitrary angle rotation is prohibited (step S252).
3), θ is set to θ ₀ (step S2523). Also,
θ _a ≒ θ _b ≒ θ _c ≒ θ _d (excluding wrong angles) (YES in step S2525), but θ _a ≒ θ _b ≒ θ _c ≒ θ _d > 0
If not (excluding wrong angle) (step S2526)
Is NO), and θ is set to θ ₀ (step S2524). If the above conditions are not satisfied (YES in step S2526), the lengths of the sides a to d are compared (step S252).
7), the side a extracted from the read area, b, c, the angle was calculated from the longest side of d theta _a, theta _b, a theta _c or theta _d adopted as an angle theta (step S2527a~S247
d). Then, other settings (step S2528) are performed, and the process returns.

FIG. 28 is a flowchart for detecting the angle θa based on the side a in step S2521 in FIG. If the side a> 0 is not satisfied (N in step S25211a
O), the angle theta _a as err (step S25219
a) Return. If side a> 0 (step S
Next, it is determined whether or not the original protrudes. If a Y _min = Y _min0, i.e., if the edge e is present (step S25212a), the X ₁₁ and X ₁ (step S25213a). Also, X _max =
If a X _max0, i.e., if the edge g is present (step S25214a), the Y ₂₀ and Y ₂ (step S25215a). Then, (Y ₂ −Y _min ) and (X _max
−X ₁ ) are compared (step S25216a),
The rotation direction is determined so that the rotation angle θ becomes smaller. That is, when (Y ₂ −Y _min ) <(X _max −X ₁ ), ta
^{_{n -1 {(X max -X 1}} ) / (Y 2 -Y min)} was an angle theta (step _{S25217a), (Y 2 -Y min} ) <(X max -
X ₁ ), tan ^-1 ｛(Y ₂ −Y _min ) / (X _max −
X ₁ )｝ is set to the angle θ (step S25218a). The angles θ _b , θ _c , and θ _d are detected in the same manner as the angle θa, but the description is omitted.

FIG. 29 is a flowchart of the size detection (FIG. 26, step S253). The size of the document sheet is detected based on the inclination angle and the length of the side of the document sheet in the reading area, the length of the side outside the reading area is set. Here, spx and spy are the sizes of the original paper to be set in the x and y directions. size_err
= If it is 1 (NO in step S2531), since the side of the document can not be detected correctly, the angle theta as theta ₀ (step S2535), usually to detect the document size (step S2536). And spx is sp
x3 and set spy to spy3 (step S
2537), and make other settings (step S253)
8). If size_err = 1 is not satisfied (step S
If YES at 2531), the skewed document size is detected (step S2532, see FIG. 41). And spx
1 and spx2 and spy1 and spy2 are compared in length (step S2533). If the lengths are significantly different (NO in step S2533), the flow advances to step S2535 to detect a normal original size. If not (YES in step S2533), spx1 is replaced by sp
x, and spy1 is set to spy (step S2).
534), and make other settings (step S253)
8).

FIG. 30 shows the detection of the skewed original size (FIG. 29,
It is a flowchart of step S2532). In this flow, the inclination angle θ and the length a of the side of the original in the reading area,
The length of the side outside the reading area is set from b, c, and d. First, the rotation direction is determined by comparing (Y ₂ −Y _min ) and (X _max −X ₁ ) (step S 25321). (Y ₂ −
Y _min) <(X _max if -X ₁₎ is the (step S2
5321), e * cosθ + a + f * sinθ is sp
x1 (step S25322); otherwise, substitute for spy1 (step S25323). Similarly, to determine the direction of rotation by comparing the (Y ₁ -Y _max) and (X ₂ -X _min) (step S25324). (Y ₁ −
Y _max) <(the case is X ₂ -X _min) (step S2
YES at 5324), g * cosθ + c + f * sinθ is sp
x2 (step S25325); otherwise, substitute for spy2 (step S25326). The rotation direction is determined by comparing (Y ₁ −Y _min ) and (X ₁ −X _min ) (step S25327). (Y ₁ −
If Y _min ) <(X ₁ -X _min ) (step S2)
YES at 5327), f * cosθ + b + e * sinθ is sp
y1 (step S25328), otherwise, substitutes spx1 (step S25329). Further, to determine the direction of rotation by comparing the (Y _max -Y ₂₎ and (X _max -X ₂₎ (step S2532A). (Y _max −
_{Y 2) <(X max -X} 2) If it is the (step S25
YES at 32A), h * cosθ + d + g * sinθ is spy
2 (step S2532B), otherwise substitute into spx2 (step S2532C). FIG.
Is normal document size detection (FIG. 29, step S253)
It is a flowchart of 6). By substituting X _max to SPX3 (step S25361), and substitutes the Y _max on Spy3 (step S25362).

FIG. 32 is a flowchart of the size setting (FIG. 26, step S254). Where spx,
spy is the size of the detected document, and cpx, c
py represents the set size of the virtual paper area 3042, and c
px_max and cpy_max represent the maximum size that can be set. If cpx <spx and cpy <spy (YES in steps S2541 and S2542), cp
A minimum fixed size satisfying x <spx and cpy <spy is set (step S2543). If the size of the detected document is larger than the maximum paper size but smaller than the maximum size that can be set by changing the length and width of the effective document size, that is, spx <cpx_max, spy ≧ cp
If y_max, spy <cpx_max (YES in step S2541, NO in step S2542, YES in step S2545), or spx ≧ cpx_
max, spx <cpy_max, spy <cpx_ma
x (NO in step S2541 and step S254
(YES at 2544, YES at step S2545), c
A minimum standard size satisfying px <spy and cpy <spx is set (step S2546), and 90 ° rotation is set (step S2547). In other cases, that is, when the effective document area sizes spx and spy are larger than the settable maximum sizes cpx_max and cpy_max (NO in step S2541 and N in step S2544).
O), set the maximum fixed size, ie, sx_ma
x is substituted for cpx, and sy_max is substituted for cpy (step S2548). Further, the angle θ is set to θ ₀ and the rotation is not performed at an arbitrary angle (step S2549). Finally, make other settings (step S254A), and return.

FIG. 33 is a flowchart for setting the rotational coordinates (FIG. 26, step S255). Where rot
_x and rot_y are coordinates representing the center of rotation with respect to the origin of the reading area. When not rotating (θ = θ ₀ )
(YES in step S2551), rot_x and rot_
Both y are set to 0 (step S2552). If it rotates (NO in step S2551), the flow branches depending on whether the detected rotation angle θ is positive or negative (step S2553). If the rotation angle θ is positive, if e> 0 (step S
(YES in 2554), X ₁₀ + e * sin ² θ is substituted for rot_x, and e * sin θ * cos θ is substituted for rot_y (step S2555). If e> 0, that is, e
= If 0 (NO in step S2554), the X ₁ r
ot_x and Y _min into rot_y (step S2556). If the rotation angle θ is negative, f> 0
If (YES in step S2557), f * sin θ
* Cos θ is substituted for rot_x, and Y ₁₀ + f * cos ² θ is substituted for ro
Substitute for t_y (step S2558). If f> 0, that is, if f = 0 (step S255)
7), Y _min is substituted for rot_x, and Y ₁ is substituted for rot_x.
y (step S2559). Then, other processing (step S255A) is performed, and the process returns.

FIG. 34 shows a destination setting (FIG. 2).
6, step S256). The destination is coordinates pmdx and pmday (based on the virtual paper origin) corresponding to the read area origin of the input image to be developed on the virtual paper. While the virtual paper area is set to the standard size, the input image size determined by extracting each side from document detection does not always match it. Therefore, when there are two or more extracted sides with priority given to the reading reference side (the rotation center side), the two sides are extracted so that the corner from which two adjacent sides can be extracted matches the corner of the virtual paper area. The destination (parallel movement amount) is set based on the set paper size. here,
spx and spy are the sizes of the detected original paper (see FIG. 40), and cpx and cpy are virtual paper areas 30.
42, and rot_x and rot_y are coordinates representing the rotation center with respect to the origin of the reading area (see FIG. 33). First, when the angle θ> 0 and the side a,
b are both positive (θ> 0 in step S2561)
And if YES in step S2562) or if the angle θ <0 and both sides b and c are positive (θ <0 in step S2561 and step S
If YES in 2563), two sides sandwiching the rotation center have been extracted. Therefore, -rot_x is changed to pmd
, And -rot_y to pmday (step S2564). Also, when the angle θ> 0 and the side a,
b are both negative (NO in step S2562,
If YES in step S2565) or if angle θ <0 and sides b and c are both negative (NO in step S2563, YES in step S2566)
), -Rot_x is substituted for pmdex,
(-Rot_y + cpy-spy) is substituted for pmday (step S2567).

If the angle θ> 0 and both sides c and d are positive (steps S2562 and S2
NO at 565 and YES at step S2568) or when angle θ <0 and both sides d and a are positive (steps S2563 and S256)
No. 6 and YES in step S2569),
(−rot_x + cpx−spx) is substituted for pmdax, and −rot_y is substituted for pmday (step S
256A). If the angle θ> 0 and both sides d and a are positive (steps S2562 and S2
565 and NO in step S2568, step S256
B is YES) or the angle θ <0 and both sides a and b are positive (step S256)
3, NO in steps S2566 and S2569, and YES in step S256C), (-rot_x + c
(px-spx) into pmdax, and (-rot_y
+ Cpy-spy) is substituted for pmday (step S256D). If none of the above conditions are met,
{-Rot_x + (cpx-spx) / 2} is converted to pmda
x, and ｛−rot_y + (cpx−spx) /
2｝ is substituted for pmday (step S256E).

FIG. 35 is a flowchart of the destination setting for 90 ° rotation (FIG. 26, step S257). If 90 ° rotation is combined, it is necessary to change the destination criterion. If θ ₉₀ = 90 (YES in step S2571), pmday is set to p
mdx, and cpx-pmdax is substituted for pmday (step S2572). Also, θ ₉₀ = 180
(YES in step S2573), cpx-
Substituting pmdx into pmdx, cpx-pmday
Is substituted for pmday (step S2574). If θ ₉₀ = 270 (Y in step S2575)
ES), substituting cpy-pmday for pmdax, p
mmax is substituted for pmday (step S257)
6). In addition, the contents of the above destination setting are
Although the case of the normal mode has been described, the binding margin shift,
When combining with a saving copy that copies a plurality of originals into one, it is also possible to make settings in consideration of this. FIG. 36 shows the setting of the sub-scanning magnification (FIG. 25, step S2).
It is a flowchart of B). First, cosθ is calculated from the inclination angle obtained by the angle detection process of document size detection.
Is calculated as the reading magnification in the sub-scanning direction (step S2).
B1). If the copying magnification has been set by the user, the reading magnification multiplied by the sub-scanning magnification is set as the sub-scanning magnification (step S2B2). Thereafter, other processing is performed (step S2B3), and the process returns.

FIG. 37 is a main flowchart of the third CPU 103 for controlling the memory unit 30. First, initial settings for initializing a RAM, a register, and the like are performed (step S31). Next, a command receiving process (step S32) and a status transmitting process (step S3)
3), image memory writing processing (step S34), compression control processing (step S35), decompression control processing (step S36), editing control processing (step S37), smoothing control processing (step S38), image memory read processing (step S38) S39) and other processing (step S3A). Next, returning to step S32,
The above processing is repeated.

FIG. 38 shows the editing control (FIG. 37, step S
37 is a flowchart of FIG. When the data for printing has been prepared (YES in step S371), the size parameters (cpx, cpy) and (spx, spy) are set (step S372), and the 90 ° unit rotation parameter (90θ) is set (step S371). (S373), the arbitrary angle rotation parameter θ is set (step S374), the rotation coordinate parameter is set (step S375), and the destination parameter (pmdx, pmday) is set (step S376). Then, other parameters are set (step S377), and the process returns.

FIG. 39 shows a fourth CP for controlling the printer unit.
It is a main flowchart of U104. After the initialization for initializing the RAM and the registers is performed (step S41), an internal timer that defines the length of one routine is set (step S42). Next, control of the development / transfer system (step S43) and control of the transport system (step S43)
44), control of the fixing system (step S45), and control of the print processing unit (step S46). Then, other processing is performed (step S47). Next, after waiting for the end of the internal timer (YES in step S48), step S4
2 and repeat the above processing. FIG. 40 is a main flowchart of the fifth CPU 105 for controlling the entire copying machine. After the initialization for initializing the RAM and the registers is performed (step S51), an internal timer that defines the length of one routine is set (step S51).
52). Next, an input data analysis process for checking input data from another CPU (step S53), a mode setting process for determining an operation mode according to the operation content (step S54), an interrupt switching process (step S55), and a mode Command setting processing (step S56), output data setting for making the command wait in the communication port (step S57), and other processing (step S58).
do. Next, waiting for the end of the internal timer (YES in step S59), the process returns to step S52, and the above-described processing is repeated.

In the above, the arbitrary angle rotation processing of the image data input from the document reading apparatus has been described. Similarly, it is also possible to process image data (with angle parameters) communicated from an external device on the network. . For example, image data input from an external device can be rotated by an arbitrary angle and printed by the print processing unit. Further, the image data read by the image reading device can be subjected to an arbitrary angle rotation process and output to an external device. In addition, image data input from an external device can be subjected to arbitrary angle rotation processing and output to the external device again.

[0045]

According to the present invention, when a document is placed on the document glass at an angle, the document is optically read at a magnification calculated in accordance with the detected document tilt angle in the document tilt angle correction process. The number of times of variable magnification is reduced. Accordingly, an increase in processing time due to electric scaling and deterioration in image quality due to insertion of lines in the electric scaling processing are eliminated, and a corrected image with good image quality is generated at high speed.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a copying machine according to the present invention.

FIG. 2 is a plan view of an operation panel of the copying machine.

FIG. 3 is a diagram illustrating an example of a system configuration including a copying machine;

FIG. 4 is a block diagram of a part of a control unit of the copying machine.

FIG. 5 is a block diagram of a part of a control unit of the copying machine.

FIG. 6 is a block diagram of a controller.

FIG. 7 is a block diagram of an image signal processing unit.

FIG. 8 is a block diagram of a memory unit.

FIG. 9 is a diagram of a memory write operation.

FIG. 10 is a diagram of a memory read operation.

FIG. 11 is a diagram for explaining input of a document image by scanning.

FIG. 12 is a diagram illustrating an example of an image of a read image.

FIG. 13 is a diagram illustrating an example of an image of a read image.

FIG. 14 is a diagram illustrating an example of an image of a read image.

FIG. 15 is a diagram illustrating a part of a process of simultaneously performing an arbitrary angle rotation process (shift shift process) and a scaling process on image data.

FIG. 16 is a diagram illustrating a part of a process of simultaneously performing an arbitrary angle rotation process (shift shift process) and a scaling process on image data.

FIG. 17 is a block diagram of an edit processing unit in the memory unit.

FIG. 18 is a diagram for describing 90 ° rotation processing of image data.

FIG. 19 is a diagram for explaining bit swap processing of image data.

FIG. 20 is a diagram illustrating an arbitrary angle rotation process (shift shift process) of image data.

FIG. 21 is a diagram illustrating a part of a normal process of simultaneously performing an arbitrary angle rotation process (shift shift process) and a scaling process on image data.

FIG. 22 is a diagram for explaining a part of a normal process of simultaneously performing an arbitrary angle rotation process (shift shift process) and a scaling process on image data.

FIG. 23 is a main flowchart of the first CPU.

FIG. 24 is a first flowchart of a main flow chart of the second CPU.
Department.

FIG. 25 is a first flowchart of a main flow of the second CPU.
Department.

FIG. 26 is a flowchart of document detection.

FIG. 27 is a flowchart of protrusion detection.

FIG. 28 is a flowchart of angle detection.

29 is a flowchart of an angle theta _a detection.

FIG. 30 is a flowchart of size detection.

FIG. 31 is a flowchart of detecting a skewed document size.

FIG. 32 is a flowchart of normal document size detection.

FIG. 33 is a flowchart of size setting.

FIG. 34 is a flowchart of setting rotation coordinates.

FIG. 35 is a flowchart of destination setting.

FIG. 36 is a flowchart of setting a 90 ° rotation destination.

FIG. 37 is a flowchart for setting a magnification in the sub-scanning direction.

FIG. 38 is a main flowchart of the third CPU.

FIG. 39 is a main flowchart of the fourth CPU.

FIG. 40 is a main flowchart of the fifth CPU.

[Explanation of symbols]

30 memory unit, 103 third CPU, 2
00 Image reading unit, 307 Editing processing unit.

Claims (3)

[Claims] An inclination detecting means for detecting an inclination angle of an original placed on an original glass; a magnification calculating means for calculating an image reading magnification based on the inclination angle detected by the inclination detecting means; Image reading means for enlarging an image according to the magnification calculated by the magnification calculation means, reading the original, converting the read image signal into an image signal, and outputting the image signal; and detecting the image signal read by the image reading means, by the inclination detecting means. And an inclination correcting unit for outputting an image signal in which the inclination of the image is corrected according to the inclination angle. 2. The image processing apparatus according to claim 1, wherein the magnification is a magnification for reading an image in a sub-scanning direction. 3. The image processing apparatus according to claim 1, further comprising a magnification setting unit configured to set a desired magnification, wherein the magnification calculation unit includes: a tilt angle detected by the tilt detection unit; An image processing apparatus for calculating an image reading magnification based on a magnification set by a magnification setting unit.