JPH11355561A - Image processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processor with which a precisely controlled .and satisfactorily magnified image can be easily provided without reading an original again by effectively utilizing and processing data preserved in a memory while increasing the number of bits, in the case of applying a fine magnifying processing to an image outputted by performing ordinary magnifying/non-magnifying processing and gradation processing. SOLUTION: When a user outputs stored data and this image is a little different from the desired size, a fine magnification circuit 107 performs fine magnification within the range of ±X%. The figure shows the process for performing the fine magnifying operation. In the figure, n-bit data from a memory 106 a subjected to an arbitrary code conversion by a code converting circuit 201 to be m'-bit data and these data are magnified by a magnification circuit 202. By increasing the number of bits through the code converting circuit 201, accuracy in variable magnification calculation is improved. Corresponding to the number of output bits after variable magnification calculation, data are turned into n-bit data again by an n-bit output circuit and outputted to a printer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image processing apparatus for reading image data, performing gradation processing, performing scaling processing, and outputting the result.

[0002]

2. Description of the Related Art In the course of the progress of OA in offices,
The mainstream of image processing apparatuses such as copiers, printers, and facsimile machines has shifted from analog to digital. Digitization is also progressing in machines that copy originals such as design drawings, which have conventionally been handled by analog machines. Manuscripts such as design drawings are not necessarily produced on the assumption that they will be copied at full size,
Since a fine structure is often made large so that it is easy to see, image processing accompanied by a scaling process is often performed. As an example of an image processing method involving a scaling process, see Japanese Unexamined Patent Publication No.
Japanese Patent Application Laid-Open No. H.643 discloses a method of storing dot density conversion information corresponding to each dot of digital image data and obtaining digital image data which is scaled in accordance with the conversion information. A method of recording image information after processing a plurality of images as in the invention described in JP-A-5-30338, and switching the direction of main scanning and sub-scanning as in the invention described in JP-A-5-83526. A method for changing the magnification in the main scanning direction afterwards has been proposed.

[0003]

However, in the scaling process, after filtering the input image data,
Alternatively, it is performed before that, and no scaling is performed after the gradation processing. This is because the original data is lost by the gradation processing, and subsequent reduction / enlargement is avoided. Until now, design drawings that have been handled by analog machines may be special paper for drawing papers or originals of a much larger size than conventional digital machines have handled. In this case, even if the original once read is scaled and output, and it is slightly too large or too small, scanning the large original again with the scanner consumes considerable labor and time. I was Also, it is easy to cause the document to be damaged, and it is necessary to avoid drawing the drawing paper such as thin paper many times to the ADF (automatic document feeder).

Further, as the copying speed of a copying machine has recently become higher, a method of temporarily storing image data in a memory and then outputting the image data has become popular in a high-speed copying machine. In order to minimize as much as possible and to shorten the compression / expansion time as much as possible,
The data after the gradation processing has been stored in the memory. However, if the data of a smaller number of bits than the original image data stored in the memory is scaled as it is, the image quality is significantly deteriorated. was there. The present invention
In view of these drawbacks, the image that has been subjected to normal scaling and equal-magnification processing and subjected to gradation processing and output is slightly different from the size intended by the user. It is an object of the present invention to provide an image processing apparatus that obtains a good scaled image easily and finely adjusted without increasing the number of bits of data stored in a memory and utilizing and processing the data again without reading a document again. .

[0005]

According to the first aspect of the present invention, input means for inputting m-bit image data for each pixel, and n-bit image data input from the input means are converted to n-bit (n <n). m), storage means for storing the n-bit data created by the gradation processing section, and scaling for scaling the n-bit data stored in the storage means A processing unit and a conversion unit that converts the n-bit data stored in the storage unit into m ′ (n <m ′ ≦ m) bits during the scaling processing by the scaling unit. Achieve the goal.

According to a second aspect of the present invention, in the image processing apparatus according to the first aspect, the above-mentioned object is achieved by generating m'-bit data by superimposing n-bit data. In the invention according to claim 3, claim 1
In the above-described image processing apparatus, the conversion unit achieves the above object by bit shifting n-bit data to generate m′-bit data. According to a fourth aspect of the present invention, in the image processing apparatus according to the first aspect, the conversion means shifts the bit of the n-bit data to a lower m ′.
The above object is achieved by generating m′-bit data by adding a random number to −n bits.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS. FIG.
1 is a diagram illustrating a configuration of an image processing unit of a digital copying machine according to an embodiment of the present invention. The data read by the scanner 100 is usually stored in a conventional scaling processing circuit 101,
The data is stored in the memory 106 via the filter processing circuit 102, the γ processing circuit 103, and the gradation processing circuit 104. By storing the data in the memory 106, when the number of copies is large, the required number of copies of the user can be copied without scanning each time. It can be turned around and output.

When the user outputs the data stored in the memory 106 and the output image data is slightly different from the size desired by the user, the fine-adjustment / magnification circuit 107 outputs ± X% (X is This is a circuit that performs zooming for fine adjustment within the range of (arbitrary integer). When the user performs a fine adjustment magnification operation, the n-bit image data stored in the memory enters the fine adjustment magnification circuit 107 and is output to the printer 108. When the user does not perform the fine-tuning operation, the data is output directly from the memory 106 to the printer 108.

FIG. 2 shows that when a fine adjustment magnification operation is performed, the printer 1 is transferred from the memory 106 through the fine adjustment magnification circuit 107.
It is a figure showing the process performed when it outputs to 08.
The n-bit data from the memory 106 is arbitrarily converted into m ′ bits by a code conversion circuit 201 and is scaled by a scaling circuit 202. By increasing the number of bits in the code conversion circuit 201, the accuracy of the scaling calculation can be increased. After the scaling, the n-bit output circuit 203 sets the number of bits to n again according to the number of output bits of the printer, and outputs the n-bit to the printer 108.

FIG. 3 is a diagram showing a process performed when data is output from the memory 106 to the printer 108 through the fine-adjustment / magnification circuit 107 when a magnification operation by bit shift is performed. The n-bit data from the memory 106 is converted to m ′ bits by performing a left bit shift in a left bit shift circuit 301, and is scaled in a scaling circuit 302. By increasing the number of bits in the left bit shift circuit 301, it is possible to increase the precision of the scaling calculation. After the scaling calculation, the n-bit output circuit 303 sets the number of bits to n again according to the number of output bits of the printer.
Output to

FIG. 4 is a diagram showing a process performed when data is output from the memory 106 to the printer 108 through the fine-adjustment / magnification / magnification circuit 107 when a magnification / magnification operation is performed by superimposing bit data. The n-bit data from the memory 106 is left-bit shifted by a left-bit shift circuit 401, and the logical sum (O) of this and n-bit data in the memory is obtained.
R), the n-bit data is converted into superimposed m 'bits, and the data is scaled by the scaling circuit 402. By increasing the number of bits in the left bit shift circuit 401, the precision of the scaling calculation can be increased. After the scaling calculation, the n-bit output circuit 403 sets the number of bits to n again according to the number of output bits of the printer.
Output to

FIG. 5 is a diagram showing processing performed when data is generated by adding a random number to bit-shifted data and output from the memory 106 to the printer 108 through the fine-adjustment / magnification circuit 107. The n-bit data from the memory 106 is left-shifted by a left-bit shift circuit 501, and is ORed with a random number generated in the random number generation circuit 500 to be converted into m′-bit data. At 502, the magnification is changed. By increasing the number of bits in the left bit shift circuit 501, it is possible to increase the accuracy of the scaling calculation. After the scaling calculation, the number of output bits of the printer is adjusted to n bits by the n-bit output circuit 503 and output to the printer 108.

FIG. 6 is an explanatory diagram of bit number conversion at the time of bit shifting. If the input image 601 has 8 bits and the output data 602 stored in the memory after filtering, scaling, gamma processing, and gradation processing is 4 bits, each bit data of p1 to p4 in the memory is By shifting to the left by 4 bits, 8-bit data 603 in which the lower 4 bits are 0 can be created, thereby performing fine adjustment magnification.

FIG. 7 is an explanatory diagram of bit number conversion for adding a random number after bit shifting. When the input image 701 has 8 bits and the output data 702 stored in the memory after filtering, scaling, gamma processing, and gradation processing is 4 bits, each bit data of p1 to p4 in the memory is By shifting to the left by 4 bits and performing an OR operation with a 4-bit random number generated by an arbitrary random number generator, 8-bit data 703 containing an arbitrary random number in the lower 4 bits can be generated. Performs fine-adjustment magnification.

FIG. 8 is an explanatory diagram of bit number conversion by superimposing data. The input image 801 has 8 bits,
When the output data 802 stored in the memory after the filtering process, the scaling process, the γ process, and the gradation process are 4 bits, each bit data of p1 to p4 in the memory is shifted left by 4 bits. By performing an OR operation with the 4-bit data of p1 to p4, 8-bit data 803 in which two bit data of p1 to p4 are overlapped can be produced, thereby performing fine-adjustment magnification.

FIG. 9 shows an example of the bit number conversion in the case where the number of bits for performing the fine scaling calculation is increased from 4 bits to 6 bits by using the bit shift method without returning the bit conversion to the number of input bits. When the input image 901 has 8 bits and the output data 902 stored in the memory after the filter processing, the scaling processing, the γ processing, and the gradation processing is 4 bits,
0 is input to the lower 2 bits corresponding to the bit-shifted bits of p1 to p4 in the memory, and 6-bit data 903 can be generated.

FIG. 10 is a flowchart in the case where the fine-adjustment magnification operation is performed. When fine scaling is operated (Step 11; Y), the stored image data is read from the memory (Step 12), the number of bits is converted to m 'bits (Step 13), and the scaling processing (Step 13) is performed. Fine-tuning magnification processing) is performed (step 14). The processed data is output in n bits according to the number of output bits of the printer (step 15), and the process returns to step 11. If the user obtains an image of the desired size (step 11;
N), this operation ends. If the user wants to further finely adjust the obtained image, the processing from step 12 to step 15 is repeated.

[0018]

According to the first aspect of the present invention, after m-bit image data is scaled to n bits (n <m), m '(n
By converting the data into <m ′ ≦ m) bits, the data after the gradation processing can be subjected to the fine adjustment magnification processing with high accuracy. According to the second aspect of the present invention, by generating the m'-bit data by superimposing the n-bit data, it is possible to easily create data for performing fine-adjustment magnification with high accuracy on the data after the gradation processing.

According to the third aspect of the present invention, the m'-bit data is generated by bit-shifting the n-bit data, thereby easily producing data for performing fine-adjustment / magnification with high precision on the data after the gradation processing. be able to. According to the fourth aspect of the present invention, the m'-bit data is generated by shifting the n-bit data by a bit and adding a random number to the lower m'-n bits, thereby performing fine-adjustment scaling on the data after the gradation processing with high accuracy. Data to be performed can be easily created.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an image processing unit according to the present embodiment.

FIG. 2 is a diagram illustrating a process when a scaling operation is performed.

FIG. 3 is a diagram illustrating a process when a scaling operation is performed by a bit shift.

FIG. 4 is a diagram illustrating processing when a magnification operation is performed by superposition.

FIG. 5 is a diagram illustrating a process in a case where a scaling operation for adding a random number by bit shifting is performed.

FIG. 6 is an explanatory diagram of bit number conversion at the time of bit shifting.

FIG. 7 is an explanatory diagram of bit number conversion when a bit is shifted and a random number is added.

FIG. 8 is an explanatory diagram of bit number conversion when overlapping.

FIG. 9 is an explanatory diagram of the bit number conversion when the bit number conversion is not returned to the input bit number.

FIG. 10 is a flowchart illustrating a procedure of a fine adjustment magnification process.

[Description of sign]

 REFERENCE SIGNS LIST 100 scanner 101 scaling processing circuit 102 filter processing circuit 103 gamma processing circuit 104 gradation processing circuit 106 memory 107 fine adjustment scaling circuit 201 code conversion circuit 202 scaling circuit 203 n-bit output circuit 301, 401, 501 left bit shift circuit 302 , 402, 502 Magnification circuits 303, 403, 503 N-bit output circuit 500 Random number generation circuit

Claims (4)

[Claims] 1. An input means for inputting m-bit image data for each pixel, and n-bit image data input from the input means
A gradation processing unit for processing so as to output in bits (n <m), a storage unit for storing the n-bit data created by the gradation processing unit, and a conversion unit for converting the n-bit data stored in the storage unit. A scaling unit for multiplying the data, and a conversion unit for converting the n-bit data stored in the storage unit into m ′ (n <m ′ ≦ m) bits during the scaling process in the scaling unit. An image processing apparatus characterized in that: 2. An image processing apparatus according to claim 1, wherein said conversion means generates m′-bit data by superimposing n-bit data. 3. An image processing apparatus according to claim 1, wherein said conversion means shifts the n-bit data by bits to generate m'-bit data. 4. The method according to claim 1, wherein said conversion means shifts the bit of the n-bit data and generates m'-bit data by adding a random number to the lower m'-n bits.
The image processing apparatus according to any one of the preceding claims.