Image processing apparatus, image forming apparatus and image processing method

Abstract

Disclosed herein is an image processing apparatus, including: a pattern-matching unit for judging whether a pixel array of a predetermined image region including a target pixel in a binary image data coincides with each pixel array of a plurality of previously prepared template data or not; and a resolution converter for preparing high-resolution image data having a higher resolution than the image data by using a pixel block composed of the predetermined number of pixels, based on a judgment result by the pattern-matching unit, wherein an output gradient value of the target pixel and position information of output pixels are set to each of the plurality of template data, and when the pattern-matching unit judges that there is template data coinciding with the pixel array of the image region, the resolution converter outputs a pixel block in which the same gradient value as the output gradient value is reproduced, based on the output gradient value and the position information of the output pixels which are set to the template data coinciding with the pixel array.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become fully understood by the detailed description and the accompanying drawings by a given by way of illustration only, and thus are not intended as a definition of the limits of the present invention, and wherein:

FIG. 1 is a block diagram illustrating the structure of main components of an image forming apparatus according to an embodiment of the present invention;

FIG. 2 is a view illustrating a relation between image data having a low resolution and image data having a high resolution;

FIG. 3 is a view illustrating output gradient values of pixel blocks;

FIG. 4 is a view illustrating an example of template data stored in ROM;

FIG. 5 is a view illustrating an example of template data stored in ROM;

FIG. 6 is a view illustrating an example of template data stored in ROM;

FIG. 7 is a view illustrating examples of position information of an output pixel set in the template data and a four-pixel block outputted based on the output gradient value;

FIG. 8A to FIG. 8D are views illustrating examples of a resolution conversion; and

FIG. 9 is a flowchart illustrating an image processing executed in the image processing apparatus.

Claims

1. An image processing apparatus, comprising: a pattern-matching unit for judging whether a pixel array of a predetermined image region including a target pixel in a binary image data coincides with each pixel array of a plurality of previously prepared template data or not; anda resolution converter for preparing high-resolution image data having a higher resolution than the image data by using a pixel block composed of the predetermined number of pixels, based on a judgment result by the pattern-matching unit,wherein an output gradient value of the target pixel and position information of output pixels are set to each of the plurality of template data, andwhen the pattern-matching unit judges that there is template data coinciding with the pixel array of the image region, the resolution converter outputs a pixel block in which the same gradient value as the output gradient value is reproduced, based on the output gradient value and the position information of the output pixels which are set to the template data coinciding with the pixel array.

2. The image processing apparatus of claim 1, wherein: when the pattern-matching unit judges that there is no template data coinciding with the pixel array of the image region, the resolution converter outputs a pixel block in which the same gradient value as that of the target pixel included in the image region is reproduced.

3. The image processing apparatus of claim 1, wherein the position information of the output pixel, which is set to each of the plurality of template data is information that is set based on positions of black pixels and white pixels surrounding the target pixel and that determines output positions of respective pixels constituting the pixel block.

4. The image processing apparatus of claim 1, wherein the output gradient value set to each of the plurality of template data is set so that an error value of the output gradient value, which is caused to the target pixel before and after a gradient conversion can be absorbed by an output gradient value of another template data which is different from the output gradient value of the template data used by the resolution converter.

5. The image processing apparatus of claim 1, wherein the output gradient value in which each pixel of the pixel block outputted when the pattern-matching unit judges that there is template data coinciding with the pixel array of the image region, can be reproduced, can be selected by operating an operation unit.

6. An image forming apparatus, comprising: the image processing apparatus of claim 1; andan image forming unit for forming an image on a material recording medium based on image data subjected to an image processing by the image processing apparatus.

7. An image processing method, comprising: judging whether a pixel array of a predetermined image region including a target pixel in a binary image data coincides with each pixel array of a plurality of previously prepared template data or not; andpreparing high-resolution image data having a higher resolution than the image data by using a pixel block composed of the predetermined number of pixels, based on a judgment result in the judging,wherein an output gradient value of the target pixel and position information of an output pixels are set to each of the plurality of template data, andwhen it is judged that there is template data coinciding with the pixel array of the image region in the judging, a pixel block in which the same gradient value as the output gradient value is reproduced, is outputted in the preparing based on the output gradient value and the position information of the output pixel which are set to the template data coinciding with the pixel array.

8. The image processing method of claim 7, wherein when it is judged that there is no template data coinciding with the pixel array of the image region in the judging, a pixel block in which the same gradient value as that of the target pixel included in the image region is reproduced, is outputted in the preparing.

9. The image processing method of claim 7, wherein the position information of the output pixel, which is set to each of the plurality of template data is information that is set based on positions of black pixels and white pixels surrounding the target pixel and that determines output positions of respective pixels constituting the pixel block.

10. The image processing method of claim 7, wherein the output gradient value set to each of the plurality of template data is set so that an error value of the output gradient value, which is caused to the target pixel before and after a gradient conversion can be absorbed by an output gradient value of another template data which is different from the output gradient value of the template data used in the preparing.

11. The image processing method of claim 7, wherein the output gradient value in which each pixel of the pixel block outputted when it is judged that there is template data coinciding with the pixel array of the image region in the judging, can be reproduced, can be selected by operating an operation unit.