Image processing apparatus and image processing method

1. An image processing apparatus including a reading sensor configured to read an original image, the image processing apparatus comprising:

an image data acquiring unit configured to acquire image data of a plurality of frames of images in which positions read by the reading sensor are shifted by less than one pixel in a main scanning direction and/or a sub-scanning direction;

a high-resolution converting unit configured to perform interpolation by using the plurality of frames of image data acquired by the image data acquiring unit to obtain image data having resolution higher than resolution of the reading sensor;

an image region information generating unit configured to generate image region information including image region bits from the image data acquired by the reading sensor;

an image region information converting unit configured to convert the image region information generated by the image region information generating unit into a format capable of being input to the high-resolution converting unit;

an image region information high-resolution converting unit configured to perform a high-resolution conversion on the image region information whose format has been converted by the image region information converting unit, by using the high-resolution converting unit; and

an image region information regenerating unit configured to regenerate the image region information, which has been converted to have the high resolution by the image region information high-resolution converting unit, as image region information having the same resolution as that of the image data converted to have the high resolution by the high-resolution converting unit,

wherein the image region information converting unit selects one image region bit from the image region bits constituting the image region information, and converts the selected image region bit to have the same bit width as that of color information of the image data,

wherein image region information that includes the image region bit whose bit width has been converted is converted to have the high resolution by the image region information high-resolution converting unit, and

wherein the image region information regenerating unit reduces the number of image region bits constituting the image region information converted to have the high resolution to 1 bit by a predetermined threshold value and allocates the image region information where the number of bits has been reduced to the image region bit selected by the image region information converting unit, to regenerate the image region information as the image region information having the same resolution as that of the image data whose resolution has been converted by the high-resolution converting unit.

2. The image processing apparatus according to claim 1 , wherein the image region information converting unit performs filter processing selected according to a feature of the selected image region bit, after the bit width is converted.

3. A method for controlling an image processing apparatus including a reading sensor configured to read an original image, the method comprising:

acquiring image data of a plurality of frames of images in which positions read by the reading sensor are shifted by less than one pixel in a main scanning direction and/or a sub-scanning direction;

performing interpolation by using the plurality of frames of acquired image data, inputting the image data to a high-resolution converting unit configured to obtain image data having resolution higher than resolution of the reading sensor, and performing a high-resolution conversion on the image data;

generating image region information including image region bits from the image data acquired by the reading sensor;

converting the generated image region information into a format capable of being input to the high-resolution converting unit;

performing a high-resolution conversion on the image region information whose format has been converted, by using the high-resolution converting unit;

regenerating the image region information, which has been converted to have the high resolution, as image region information having the same resolution as that of the image data converted to have the high resolution;

selecting one image region bit from the image region bits constituting the image region information, and converting the selected image region bit to have the same bit width as a bit width of color information of the image data;

performing a high-resolution conversion on image region information that includes the image region bit whose bit width has been converted; and

reducing the number of image region bits constituting the image region information converted to have the high resolution to 1 bit by a predetermined threshold value and allocating the image region information where the number of bits has been reduced to the selected image region bit, to regenerate the image region information as the image region information having the same resolution as that of the image data whose resolution has been converted.

4. The method according to claim 3 , further comprising:

performing filter processing selected according to a feature of the selected image region bit, after the bit width is converted.

5. A non-transitory computer-readable storage medium storing a program for causing a computer to execute a method for controlling an image processing apparatus including a reading sensor configured to read an original image, the method comprising:

acquiring image data of a plurality of frames of images in which positions read by the reading sensor are shifted by less than one pixel in a main scanning direction and/or a sub-scanning direction;

performing interpolation by using the plurality of frames of acquired image data, inputting the image data to a high-resolution converting unit configured to obtain image data having resolution higher than resolution of the reading sensor, and performing a high-resolution conversion on the image data;

generating image region information including image region bits from the image data acquired by the reading sensor;

converting the generated image region information into a format capable of being input to the high-resolution converting unit;

performing a high-resolution conversion on the image region information whose format has been converted, by using the high-resolution converting unit;

regenerating the image region information, which has been converted to have the high resolution, as image region information having the same resolution as that of the image data converted to have the high resolution;

selecting one image region bit from the image region bits constituting the image region information, and converting the selected image region bit to have the same bit width as a bit width of color information of the image data;

performing a high-resolution conversion on image region information that includes the image region bit whose bit width has been converted; and

reducing the number of image region bits constituting the image region information converted to have the high resolution to 1 bit by a predetermined threshold value and allocating the image region information where the number of bits has been reduced to the selected image region bit, to regenerate the image region information as the image region information having the same resolution as that of the image data whose resolution has been converted.