JP3904892B2 - Image processing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image processing apparatus, and more particularly, to an image processing apparatus such as a digital copying machine having a function for converting an input image size and outputting it.
[0002]
[Prior art]
Some conventional image processing apparatuses include an electronic scaling unit for changing and outputting an input image size in the main scanning direction. In such a conventional electronic scaling processing unit, when changing the scaling factor in the same line and outputting, since the output pixel interval differs for each part, the coordinates of all the output pixels are calculated in advance by the CPU or the like. Needed to be stored in memory.
[0003]
First, the configuration of a conventional electronic scaling unit will be described with reference to FIG. FIG. 9 is a block diagram showing a schematic configuration of a conventional electronic scaling unit.
As shown in FIG. 9, the electronic scaling unit 50 in the conventional image processing apparatus includes an enlargement line memory 51, an output image density calculation unit 52, an output coordinate position storage memory 53, and a reduction line memory 54. Has been.
In the electronic scaling processing unit 50, the image data subjected to the filter processing by the filter processing unit is stored in the enlargement line memory 51. The enlargement image data (pixel density) is read out as necessary and input to the output image density calculation unit 52, and is used for density calculation of the output image.
When the enlargement process is performed, the readout signal to the enlargement line memory 51 is thinned out and output. However, when the same magnification process or the reduction process is performed, the readout signal is not subjected to such a thinning control. It is output to the output image density calculation unit 52 as it is.
[0004]
The output image density calculation unit 52 obtains the coordinates of the output pixel from the output coordinate position storage memory 53 and performs an operation based on the image data (pixel density) read from the enlargement line memory 51 to obtain a pixel of the output pixel. Calculate the concentration. The calculated image data (pixel density) is written in the reduction line memory 54. Further, when the enlargement process is performed, the data is written as it is without being subjected to the write control. However, when the reduction process is performed, the writing thinning is performed according to the reduction ratio.
[0005]
Next, the electronic scaling processing unit 50 described above will be described in more detail with reference to FIG. FIG. 10 is a block diagram showing a configuration of an output image density calculation unit 52 constituting the conventional electronic scaling processing unit 50 shown in FIG.
As shown in FIG. 10, the output image density calculation unit 52 constituting the conventional electronic scaling processing unit 50 includes an output coordinate position storage memory 53, a line detection unit 61, an input pixel position storage unit 62, and an input pixel density storage unit. 63, an output pixel density calculation unit 64, an output thinning creation unit 65, and an input pixel capture unit 66.
[0006]
In order to change the magnification, the user operates an operation unit such as a panel and inputs the magnification and coordinates for changing the magnification. The CPU 60 constituting the image processing device calculates the output position of the interpolated pixel after scaling on the output pixel coordinate axis with the horizontal synchronization signal input position as the origin, based on the input value. The calculated output pixel position is stored in the output coordinate position storage memory 53.
That is, the output coordinate position storage memory 53 stores the coordinates of each output pixel for one line. As the output coordinate position storage memory 53, a line memory is generally used.
[0007]
When the line detection unit 61 detects a horizontal synchronization signal, the input pixel coordinates stored in the input pixel position storage unit 62 are reset.
When the processing of one input pixel is completed, the next input pixel is read from the enlargement line memory 51 (see FIG. 9). The value read is the pixel density of the input pixel. Here, the input pixel reading interval varies depending on the magnification. For example, when the magnification is 200%, since an output of 2 pixels is obtained from an input of 1 pixel, reading is performed once for 2 outputs. In addition, if the magnification is 50%, one pixel output is obtained from two pixel inputs, so that two readings are performed for one output.
[0008]
Such adjustment of the input pixel capturing interval is performed by the input pixel capturing unit 66. The input pixel capture unit 66 outputs a read signal to the enlargement line memory 51 (see FIG. 9) at the created capture interval.
Which input pixel is currently used is stored in the input pixel position storage unit 62. The read density of the input pixel is stored in the input pixel density storage unit 63 including a line memory and used for calculating the image density of the output pixel.
[0009]
The output pixel density calculation unit 64 calculates the output pixel density based on the input pixel density and the output coordinates. Specifically, the density of the output pixel is calculated by primary interpolation processing using the image density of the input pixels on both sides sandwiching the output pixel and the internal division ratio of the output pixel position to the input pixel position.
[0010]
Next, a method for calculating the output pixel density will be described with reference to FIG.
The following equation is used to calculate the output pixel density.
(Density of output pixel C) = (Density of input pixel A) × (BC) / (B−A) + (Density of input pixel B) × (C−A) / (B−A)
[0011]
Here, C is the coordinates of the output pixel with the horizontal synchronization signal as the origin, and this is a value calculated by the CPU 60 and stored in the output coordinate position storage memory 53.
Note that the output pixel density may be calculated using the internal division ratio (D (= C−A)) of each output pixel without using the coordinates with the horizontal synchronization signal as the origin.
[0012]
That is, the output pixel density can be calculated using the following equation.
(Density of output pixel C) = (Density of input pixel A) × (B−A−D) / (B−A) + (Density of input pixel B) × D / (B−A)
[0013]
The output pixel density calculated in this way is written into the reduction line memory 54. When the reduction process is performed, the writing to the reduction line memory 54 is thinned and written, and this thinning signal is created by the output thinning creation unit 65. In the reduction thinning, the thinning interval calculated in advance by the CPU 60 may be stored in the output thinning creation unit 65, or the output pixel position stored in the output coordinate position storage memory 53 and the current output position. By using a comparator, the thinning interval may be created.
[0014]
[Problems to be solved by the invention]
However, the conventional image processing apparatus described above has the following problems. In other words, in order to partially change the scaling factor on the same line in the electronic scaling process, since the output pixel interval is partially different, all the positions of the output pixels on the coordinate axis with the horizontal synchronization signal as the origin are all I had to remember it.
Therefore, in order to store the output coordinates of the pixels for one line, a large-scale storage device such as a line memory is necessary, which causes a problem of increasing the circuit scale and cost.
[0015]
The present invention has been proposed in view of the above-described problems. In an image processing apparatus such as a digital copying machine having a scaling processing function for converting an input image size and outputting the line, an interpolation output position coordinate storage line is provided. The objective is to make it possible to change the scaling factor in the main scanning direction at any position in one line without using a memory, to eliminate the memory for storing coordinates, to reduce the circuit scale, and to reduce the manufacturing cost And
[0016]
[Means for Solving the Problems]
In order to achieve the above-described object, the image processing apparatus according to the present invention prepares a plurality of magnifications that can be changed in the main scanning direction, and introduces a circuit that can change the magnifications at arbitrary positions. In addition, a circuit for calculating the output coordinates of the Nth pixel was introduced by performing an operation based on the above-described scaling factor for the output position of the (N-1) th pixel.
[0017]
That is, the image processing apparatus according to the present invention provides an output coordinate calculation for sequentially calculating the coordinates of the output image position in an image processing apparatus having an electronic scaling unit for electronic scaling of image data in the main scanning direction. Means, Output image density calculation means for sequentially calculating the output image density, The output coordinate calculation means In consideration of input information input by a user of an image area to be enlarged or reduced at an arbitrary position or information automatically calculated by image characteristics of the image area, the size of the image area and the output paper width Then, a scaling factor for enlargement or reduction is calculated from the above, and when calculating the output coordinates sequentially, the calculated scaling factor is changed so that all the input coordinates on one page fit on one page of the output image. It is characterized by that.
[0018]
In the image processing apparatus, the output coordinate calculation unit is configured to calculate the output coordinates of the Nth output pixel by adding a constant to the output coordinates of the (N-1) th output pixel.
[0019]
The image processing apparatus further comprises output image density calculation means for calculating output image density,
The output image density calculation means is configured to calculate the output image density by linear interpolation processing using two input pixel densities sandwiching the output pixel and the position of the output pixel with respect to the two input pixels.
[0020]
In the image processing apparatus, the output coordinate calculation means prepares a plurality of constants to be added to the output coordinates, and selects and changes any one of the plurality of constants during the process on the same line. Configure as possible.
[0023]
Further, in the image processing apparatus, the output coordinate calculation means has a buffer coordinate area for gradually changing the constant to be added in the vicinity of the coordinate to change the constant to be added. The constant is changed slowly.
[0024]
In the image processing apparatus, the output coordinate calculation unit is configured to be able to arbitrarily change the width of the buffer coordinate area.
[0025]
In the image processing apparatus, the output coordinate calculation means is configured to change the constant gently within the buffer coordinate area based on the moving average of the constant.
[0026]
The image processing apparatus is configured such that when the enlargement process is performed in a predetermined area in one line, the reduction process is performed in the remaining area.
[0027]
In the image processing apparatus, when the reduction process is performed in a predetermined area in one line, the enlargement process is performed in the remaining area.
[0028]
Further, the image processing apparatus is configured to use a region separation process to perform a reduction process when a photograph area is determined and to perform an enlargement process when a character portion is determined.
[0029]
As described above, the image processing apparatus according to the present invention is configured to calculate the next output pixel position by calculation from the output coordinate position of the previous pixel, so that by replacing the calculation coefficient (magnification factor), The output coordinate position can be sequentially calculated by changing the output coordinate interval for each pixel. Although such a configuration increases the number of circuits for sequential calculation, the increase in this circuit is negligible compared to the circuit scale of the line memory.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an image processing apparatus according to the present invention will be described below using specific examples shown in the drawings.
[0031]
FIG. 1 is a block diagram showing a schematic configuration of a digital copying machine which is an embodiment of an image processing apparatus according to the present invention.
As shown in FIG. 1, the image processing apparatus 1 according to the present invention includes an image capturing unit 2, an image processing unit 3, an image memory 4, and an image forming unit 5.
[0032]
The image capturing unit 2 includes a CCD 6, and the image capturing unit 2 captures an image. Image data read from the CCD 6 of the image capturing unit 2 is sent to the image processing unit 3.
The image processing unit 3 includes a shading correction unit 7, an automatic exposure unit 8, a region separation / filter processing unit 9, an electronic scaling processing unit 10, and an error diffusion unit 11.
[0033]
In the image processing unit 3, shading correction is performed on the image captured by the CCD 6 by the shading correction unit 7, and element variation of the CCD 6 is corrected. Subsequently, the image data that has undergone the shading correction is sent to the automatic exposure unit 8, where background removal and brightness correction are performed. Subsequently, the image data that has been subjected to the automatic exposure processing is sent to the region separation / filter processing unit 9 and subjected to filter processing according to an image such as a character or a photograph. Subsequently, the image data that has been subjected to the filter processing is sent to the electronic scaling processing unit 10, and enlargement / reduction scaling processing is performed.
[0034]
Subsequently, the image data after the electronic scaling process is sent to the error diffusion unit 11, binarized, and stored in the image memory 4. Further, the image data read from the image memory 4 is sent to an image forming unit (LSU unit or the like) 5 and printed out on paper.
Although not shown, the image processing apparatus 1 includes an operation panel unit for inputting operation content, a display unit for displaying the operation content, a control unit for controlling the entire image processing device, and the like. ing.
[0035]
Next, electronic scaling processing and input / output coordinate conversion processing will be described with reference to FIG. FIG. 2 is an explanatory diagram of the electronic scaling process and the input / output coordinate conversion process.
The electronic scaling process is a process for converting and outputting the number of input pixels. Here, the straight line shown in the upper part of FIG. 2 shows the input coordinate axis, and the straight line shown in the lower part of FIG. 2 shows the output coordinate axis. In the example shown in FIG. 2, enlargement is performed twice.
[0036]
In the electronic scaling process, the number of pixels on the input coordinate axis is converted and output on the output coordinates. The creation interval of the output pixels is determined by the scaling factor. That is, the larger the enlargement ratio, the denser the pixels are created and the number of pixels increases. On the other hand, the larger the reduction ratio, the sparsely created and the number of pixels decreases. For example, when enlargement is performed 8 times, 8 output pixels are created for 1 input pixel. Further, in the case of performing reduction by 1/8, one output pixel is created for eight input pixels.
The pixel density of the output pixel is created according to the density of the input pixels on both sides of the output pixel and the distance from the input pixels on both sides of the output pixel.
[0037]
Next, the electronic scaling processing unit will be described in more detail with reference to FIG. FIG. 3 is a block diagram illustrating a configuration of an output image density calculation unit included in the electronic scaling processing unit 10 illustrated in FIG. In the output image density calculation unit shown in FIG. 3, there is no output coordinate position storage memory that exists in the past, but this is because the output image density calculation unit is replaced with a circuit in this embodiment.
[0038]
As shown in FIG. 3, the output image density calculation unit 20 includes a scaling factor calculation unit 21, an input pixel capturing unit 22, a line detection unit 23, a magnification change position storage unit 24, a scaling factor storage unit 25, and an output coordinate calculation unit 26. , An output coordinate storage unit 27, an interpolation ratio calculation unit 28, an input pixel position storage unit 29, an input pixel density storage unit 30, an output pixel density calculation unit 31, and an output thinning creation unit 32.
[0039]
In the output image density calculation unit 20, the scaling factor input by the user using an input device such as a key is stored in the scaling factor storage unit 25. The variable magnification storage unit 25 stores all the variable magnifications used for one copy output. That is, when a partial copy is made at 50% and the remaining part is copied at 150%, the magnifications of 50% (magnification α) and 150% (magnification β) are stored.
[0040]
Similarly, the magnification change position input using the input device is stored in the magnification change position storage unit 24. The magnification change position storage unit 24 stores all of the magnification change positions used for one copy output. That is, when copying at 50% (position a) in part A and copying at 150% (position b) in part B, the boundary of part A and the boundary of part B are stored. The stored position information is a position on the coordinate axis with the horizontal synchronization signal as the origin.
[0041]
In addition, when automatically adjusting the scaling factor according to the region separation result, that is, when the photograph is reduced to a small size and the character is greatly changed, based on the region separation information obtained from the region separation / filter processing unit, A scaling factor calculation unit 21 calculates a scaling factor. In this case, the boundary between the photograph and the character is stored in the magnification change position storage unit 24.
[0042]
The line detection unit 23 detects a horizontal synchronization signal. When a horizontal synchronization signal is input to the line detection unit 23, a reset signal is input to the output coordinate calculation unit 26, and the output pixel coordinates are reset. The reset signal is also input to the input pixel position storage unit 29, and the input pixel coordinates are reset.
[0043]
The input pixel position storage unit 29 stores the position of the input pixel used for calculation of the current output pixel density from the horizontal synchronization signal. In addition, since the input pixels on both sides sandwiching the output pixel coordinates are necessary for calculating the output pixels, the input coordinates for two pixels are stored in the input pixel position storage unit 29.
[0044]
The output coordinate calculation unit 26 calculates the coordinates of the output pixel. In the output coordinate calculation unit 26, the scaling factor (α, β) stored in the scaling factor storage unit 25 with respect to the output coordinate (N−1) one pixel before stored in the output coordinate storage unit 27. Appropriate scaling factors are selected and added to create output coordinates (N).
[0045]
Here, the reciprocal of the magnification set by the user is input to the variable magnification. For example, if the input pixel interval is 8192 input coordinates and the user sets 50% (0.5 times), 8192 / 0.5 = 16384 is set as the scaling factor. If 200% (twice) is set, 8192/2 = 4096 is set. By setting the reciprocal in this way, if the reduction ratio is large, the output coordinate interval becomes long and the number of output pixels decreases. Conversely, if the enlargement ratio becomes large, the output pixel interval becomes short and the number of output pixels increases.
When the output coordinate (N) is calculated, the output coordinate storage unit replaces (N−1) with (N).
[0046]
When the output coordinates exceed the value stored in the magnification change position storage unit 24, the magnification used for creating the output coordinates is changed. Here, the contents stored in the magnification change position storage unit 24 can be arbitrarily changed. Further, as described above, the change of the magnification ratio may be performed by comparing the output coordinate positions or by comparing the input coordinate positions.
[0047]
The interpolated internal ratio calculation unit 28 calculates a relative position of the output pixel with respect to the input pixel, that is, a ratio at which the output pixel internally divides the input pixel, based on the input pixel position and the output pixel position. For example, if an output pixel is created at a point that internally divides two input pixels by 1: 3, the output pixel density calculation unit 31 creates an output pixel density corresponding to the internal division ratio.
[0048]
The input pixel is read from the enlargement line memory. A read control signal to the expansion line memory is generated by the input pixel capturing unit 22. What is read from the expansion line memory is the pixel density of the input pixel.
[0049]
The input pixel capturing unit 22 is a part that performs input pixel capturing control, and controls and outputs a read permission signal to the enlargement line memory. Since the input pixel capture timing varies depending on the magnification, the input pixel is captured at a timing depending on the magnification. That is, when the zoom ratio is 50%, two pixels are read for one output pixel. When the zoom ratio is 200%, one pixel is read for every two output pixels. The input pixel density storage unit 30 stores the density of the read pixel. The input pixel density storage unit 30 stores the density of input pixels for two pixels on both sides of the output pixel.
[0050]
The output pixel density calculation unit 31 calculates the density of the output pixel. That is, the output density is calculated using the following formula based on the input pixel density and the interpolation internal ratio.
When the interpolation internal ratio calculation unit 28 creates the interpolation internal ratio “a” and the interpolation internal ratio “a”,
Output pixel density = input pixel density A × interpolation internal ratio “A” + input pixel density B × interpolation internal ratio “A”
It becomes.
However, the interpolation internal ratio “a” and the interpolation internal ratio “a” satisfy the relationship of interpolation internal ratio “a” + interpolation internal ratio “a” = 1.
The calculation of the output pixel density is performed by the primary interpolation.
[0051]
The calculated output pixel density is written in the reduction line memory. When the reduction process is performed, the writing to the reduction line memory is thinned out. This thinning signal is generated by the output thinning creation unit 32. The output decimation creating unit 32 creates a decimation signal corresponding to the reduction rate and outputs it to the reduction line memory. That is, the current coordinate and the output pixel position output by the output coordinate calculation unit 26 are compared, and a write signal is output at a timing when output is necessary.
[0052]
Next, a processing procedure in the image processing apparatus according to the present invention will be described with reference to FIG. FIG. 4 is a flowchart showing a processing procedure in the image processing apparatus according to the present invention.
[0053]
When the processing is started in the image processing apparatus according to the present invention, as shown in FIG. 4, the magnification ratio changed by the user and the change position of the magnification ratio in the main scanning direction are set by key input (S1).
When the key input is completed, the process is in a standby state until the page signal indicates the start of the page area (S2). When the page becomes an effective area, the input of the horizontal synchronization signal (sync) is determined (S3).
[0054]
Here, when the horizontal synchronization signal (sync) is input, the input / output pixel position is reset to "0" (S4). On the other hand, when the horizontal synchronization signal (sync) is not input, the scaling factor is added to the output pixel position (N-1), and the output pixel position (N) is calculated (S5).
Subsequently, it is determined whether the output pixel position is equal to the change position of the scaling factor set by the user (S6). Here, when the output pixel position is equal to the change position, the magnification is changed (S7). By this change, it is possible to partially change the magnification even within the same page.
[0055]
Subsequently, the relative positional relationship between the calculated output pixel position and the input pixel position, that is, the internal division ratio of the output pixel to the input pixel is calculated (S8). Subsequently, the output pixel density calculation unit 31 calculates the output pixel density by linear interpolation based on the input pixel density and the internal division ratio (S9).
When the output pixel density is calculated, the presence / absence of a page signal is determined (S10). If the page signal has ended, the process ends. If the page signal is valid, the process after the horizontal sync signal detection process (S3) is repeated.
[0056]
Next, using FIG. 5 and FIG. 12, the storage contents of the output coordinate storage section in the image processing apparatus according to the present invention and the storage contents of the output coordinate storage section (output coordinate position storage memory) in the conventional image processing apparatus. Explain the difference. FIG. 5 is an explanatory diagram of the storage contents of the output coordinate storage unit in the image processing apparatus according to the present invention, and FIG. 12 is an explanatory diagram of the storage contents of the output coordinate storage unit (output coordinate position storage memory) in the conventional image processing apparatus. It is.
[0057]
First, the contents stored in the output pixel position storage unit (output coordinate position storage memory) in the conventional image processing apparatus will be described.
The upper part of FIG. 12 shows the relationship between the pixel and the output pixel position, and the lower part shows the contents stored in the output pixel position storage unit (output coordinate position storage memory).
[0058]
In the upper part of FIG. 12, the left end is the position of the horizontal synchronizing signal, that is, the origin of the output pixel position, and the central part is the changing point of the magnification. A conventional output pixel position storage unit (output coordinate position storage memory) stores all distances from the horizontal synchronization signal for each pixel. The calculation of the output pixel position is performed by a process of reading the position from the memory for each output pixel.
[0059]
Next, the contents stored in the output pixel position storage unit in the image processing apparatus of the present invention will be described.
The upper part of FIG. 5 shows the relationship between the pixel and the output pixel position, the lower left part shows the storage contents of the output pixel position storage unit, and the lower part center shows the storage contents of the magnification change position storage part. Yes, on the right side of the lower row, the contents stored in the scaling factor storage unit are shown.
[0060]
In the upper part of FIG. 5, the left end is the position of the horizontal synchronizing signal, that is, the origin of the output pixel position, and the central part is the change point of the scaling factor. The output pixel position storage unit in the image processing apparatus of the present invention stores a scaling factor, that is, the number to be added from the previous output pixel position. The calculation of the output pixel position is performed by a process of adding a scaling factor to the previous output pixel. The scaling factor storage unit stores a plurality of scaling factors so that the scaling factor can be changed during the same process, and replaces the values when an instruction to change the scaling factor is given. Further, the change point of the variable magnification is stored in the magnification change position storage unit.
[0061]
Next, the buffer coordinate area will be described with reference to FIG. FIG. 6 is an explanatory diagram of the buffer coordinate area.
If there is a sudden change in magnification during the same process, there may be a problem that the image is difficult to read near the boundary line. Therefore, in the image processing apparatus according to the present invention, a buffering area is provided in the vicinity of the boundary where the scaling ratio changes, and the scaling ratio is gradually changed within the buffering area.
[0062]
In FIG. 6, it is assumed that the line flows from the left side to the right side. As shown in FIG. 6, the scaling process is doubled at the initial stage of the line, but the case where the process is changed to the process of 8 times in the middle of the line is considered. In the example shown in FIG. 6, the magnification is not changed from 2 times to 8 times suddenly, but the magnification is changed step by step to 2 times, 3 times, 5 times, and 8 times. By performing such processing, it is possible to prevent a sudden image change from occurring at the boundary portion.
[0063]
Here, the width of the buffer area can be set arbitrarily, and the width of the area where the magnification can be changed can be changed. If this width is wide, a more gradual change in image quality can be obtained. As a means for slowly changing the scaling factor, for example, a method of taking a moving average of the scaling factor can be considered.
[0064]
Next, an output area adjustment method will be described. FIG. 7 is an explanatory diagram illustrating Example 1 of the output region adjustment method, and FIG. 8 is an explanatory diagram illustrating Example 2 of the output region adjustment method.
[0065]
First, a first embodiment of the output region adjustment method will be described.
In FIG. 7A, it is assumed that the image of the central portion (region B) is to be enlarged. Here, since the image is input from the left end (region A side), if the central portion is enlarged with the left portion being the same magnification, the image of region C will be protruded from the output image and lost.
[0066]
Therefore, as shown in FIG. 7B, the central portion is enlarged, and the other portions (regions A and C) are reduced so as not to cause image loss. Here, the user sets the magnification ratio of the area B and the area width of the area B by key setting. It is assumed that the magnification and magnification change positions of the remaining areas A and C are calculated by the magnification calculation unit 21 and the magnification change position storage unit 24 in FIG. The areas A and C and the magnification can be calculated from the magnification and area B and the output paper width.
[0067]
Next, a second embodiment of the output region adjustment method will be described.
As shown in FIG. 8A, it is assumed that there is a document in which photographs and characters are mixed. Here, even if the photo area is reduced, it is difficult to damage the entire image. Therefore, the photo portion is reduced and the character portion is enlarged (FIG. 8B). By performing such processing, it is possible to make the character portion easy to read without damaging the entire image. Here, the region separation processing of the photograph and character uses the region separation processing result of the region separation / filter processing unit 9 in FIG.
[0068]
【The invention's effect】
Since the image processing apparatus according to the present invention has the above-described configuration, the following effects can be obtained.
[0069]
That is, according to the image processing apparatus of the present invention, the output coordinate calculation means sequentially calculates the coordinates of the output image position, and the scaling factor can be changed at an arbitrary position. For this reason, by changing the magnification ratio partially, it is possible to adjust the visibility according to the importance of information even on the same document. For example, when processing a document in which characters and photos are mixed, it is possible to enlarge only the character portion for easy reading. In addition, by sequentially calculating the output image position, a large-scale storage device is not required.
[0070]
Further, according to the image processing apparatus of the present invention, the output coordinates of the Nth output pixel can be calculated by adding a constant to the output coordinates of the (N−1) th output pixel. For this reason, the coordinates memorized for calculating the output coordinates can be saved. That is, by calculating the Nth pixel from the (N-1) th pixel without storing all the output coordinates for one line, only the storage capacity of the coordinates of the N-1th pixel is required.
[0071]
Further, according to the image processing apparatus of the present invention, the output image density is calculated by the primary interpolation process using the input pixel density sandwiching the output pixel and the position of the output pixel with respect to the input pixel. Therefore, the output image density can be calculated only from the input pixel density and the output pixel position, and the circuit scale can be reduced.
[0072]
In addition, according to the image processing apparatus of the present invention, a plurality of constants to be added to the output coordinates are prepared, and any one of the plurality of constants can be selected and changed during the processing on the same line. Yes. For this reason, it is possible to execute partially independent scaling by changing the scaling ratio in the same line.
[0075]
Further, the image processing apparatus according to the present invention has a buffer coordinate area for gradually changing the constant to be added in the vicinity of the coordinate to change the constant to be added. The constant is changed. For this reason, it is possible to smoothly change the magnification without causing a sense of incongruity without causing a sudden change in the magnification.
[0076]
Further, according to the image processing apparatus of the present invention, the width of the buffer coordinate area can be arbitrarily changed. For this reason, even if there is a sudden change in magnification, the smoothness of the boundary point can be adjusted by increasing the width of the buffer region.
[0077]
Further, according to the image processing apparatus of the present invention, the constant is gradually changed in the buffer coordinate area based on the moving average of the constant. For this reason, the scaling factor can be changed smoothly with a simple configuration.
[0078]
Further, according to the image processing apparatus of the present invention, when the enlargement process is performed in a predetermined area in one line, the reduction process is performed in the remaining area. For this reason, even in a document area for which enlargement is not designated, the entire document area can be reduced and output.
[0079]
Further, according to the image processing apparatus of the present invention, when the reduction process is performed in a predetermined area in one line, the enlargement process is performed in the remaining area. For this reason, the reduction process can be performed on only a part without creating a blank part in the output.
[0080]
Further, according to the image processing apparatus of the present invention, using the region separation process, the reduction process is performed when the photograph area is determined, and the enlargement process is performed when the character portion is determined. Therefore, by reducing the photo area and enlarging the character area, easy-to-read character output can be performed without losing the entire image.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of an image processing apparatus according to the present invention.
FIG. 2 is an explanatory diagram of an electronic scaling process and an input / output coordinate conversion process.
FIG. 3 is a block diagram showing a configuration of an electronic scaling processing unit.
FIG. 4 is a flowchart showing a processing procedure in the image processing apparatus according to the present invention.
FIG. 5 is an explanatory diagram of contents stored in an output coordinate storage unit in the image processing apparatus according to the present invention.
FIG. 6 is an explanatory diagram of a buffer coordinate area.
FIG. 7 is an explanatory diagram illustrating Example 1 of an output region adjustment method.
FIG. 8 is an explanatory diagram illustrating Example 2 of an output region adjustment method.
FIG. 9 is a block diagram showing a schematic configuration of a conventional electronic scaling unit.
FIG. 10 is a block diagram showing a configuration of an output image density calculation unit constituting a conventional electronic scaling processing unit.
FIG. 11 is an explanatory diagram of a calculation method of output pixel density.
FIG. 12 is an explanatory diagram of storage contents of an output coordinate position storage memory in a conventional image processing apparatus.
[Explanation of symbols]
1 Image processing device
2 Image capture unit
3 Image processing section
4 Image memory
5 Image forming section
6 CCD
7 Shading correction part
8 Automatic exposure section
9 Region separation / filter processing section
10 Electronic magnification processing section
11 Error diffusion section
20 Output image density calculator
21 Variable magnification calculator
22 Input pixel capture unit
23 Line detector
24 Magnification change position storage unit
25 Variable magnification memory
26 Output coordinate calculator
27 Output coordinate storage unit
28 Interpolation internal ratio calculation part
29 Input pixel position storage unit
30 Input pixel density storage
31 Output pixel density calculator
32 Output decimation generator
50 Electronic scaling unit
51 Line memory for expansion
52 Output image density calculator
53 Output coordinate position memory
54 Line memory for reduction
53 Output coordinate position memory
60 CPU
61 Line detector
62 Input pixel position storage unit
63 Input pixel density storage unit
64 Output pixel density calculator
65 Output thinning creation section
66 Input pixel capture unit

Claims (8)

In an image processing apparatus provided with an electronic scaling unit for electronic scaling of image data in the main scanning direction,
Output coordinate calculation means for sequentially calculating the coordinates of the output image position;
Output image density calculating means for sequentially calculating output image density;
With
The output coordinate calculation means considers input information input by a user of an image area to be enlarged or reduced at an arbitrary position or information automatically calculated based on image characteristics of the image area, and determines the size of the image area. A scaling factor for enlargement or reduction is calculated from the output width and the output paper width, and when the output coordinates are calculated sequentially, the calculated scaling factor is changed so that all the input coordinates of one page are one page of the output image. An image processing apparatus characterized in that it fits in 2. The image processing according to claim 1 , wherein the output coordinate calculation unit calculates the output coordinates of the output pixel of the Nth pixel by adding a constant to the output coordinates of the output pixel of the (N−1) th pixel. apparatus. The output image density calculating means calculates an output image density by linear interpolation processing using two input pixel densities sandwiching an output pixel and a position of the output pixel with respect to the two input pixels. Item 8. The image processing apparatus according to Item 1.   The output coordinate calculation means prepares a plurality of constants to be added to the output coordinates, and can select and change any one of the plurality of constants during the processing in the same line. The image processing apparatus according to claim 2. The output coordinate calculation means has a buffer coordinate area for gradually changing the constant to be added in the vicinity of the coordinate to change the constant to be added, and the constant gradually changes in the buffer coordinate area. The image processing apparatus according to claim 2, which is configured as described above. The image processing apparatus according to claim 5, wherein the output coordinate calculation unit can arbitrarily change a width of the buffer coordinate area . The image processing apparatus according to claim 5, wherein the output coordinate calculation unit gently changes the constant in the buffer coordinate area based on a moving average of the constant . The image processing apparatus according to claim 1, wherein a reduction process is performed when a photograph area is determined using an area separation process, and an enlargement process is performed when a character portion is determined .

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