IMAGE PROCESSING DEVICE PRODUCING REDUCED IMAGE

• US 20110222076A1
• Filed: 02/15/2011
• Published: 09/15/2011
• Est. Priority Date: 03/15/2010
• Status: Active Grant

• Current Assignee: Brother Kogyo Kabushiki Kaisha
• Original Assignee: Brother Kogyo Kabushiki Kaisha
• Inventors: KUNO, Masashi
• Granted Patent: US 8,599,430 B2
• Time in Patent Office: Days
• US Class Current: 358/1.2
• CPC Class Codes: G06T 3/40 Scaling of whole images or parts thereof, e.g. expanding or contracting
• CPC Class Codes: H04N 1/40068 Modification of image resolution, i.e. determining the values of picture elements at new relative positions H04N1/3935 takes precedence

Abstract

An image processing device includes an original image data acquiring unit and a reducing unit. The original image data acquiring unit acquires original image data indicative of an original image. The original image data includes a plurality of sets of original pixel data, the original image having a first resolution and a first size. The original image is divided into a plurality of original grids. Each original grid corresponds to a set of original pixel data. The reducing unit creates reduced image data by performing a reduction process on the original image data. The reduced image data includes a plurality of sets of reduced pixel data. The reduced image data indicates of a reduced image having a second resolution lower than the first resolution and a second size same as the first size. The reduced image is divided into a plurality of reduced grids. Each reduced grid corresponds to a set of reduced pixel data. The reducing unit includes an acquiring unit and a reduced pixel data producing unit. The acquiring unit acquires, for each set of reduced pixel data, at least one set of original pixel data satisfying a following condition that the at least one set of original pixel data corresponds to the original grid whose part is superposed on the reduced grid corresponding to the each set of reduced pixel data when the reduced image is partially superposed on the original image such that the reduced image is shifted, from a original position at which the reduced image is entirely superposed on the original image, by a prescribed length shorter than a length of one original grid. The reduced pixel data producing unit produces the reduced pixel data by calculating a weighted average of the at least one set of original pixel data acquired by the acquiring unit based on size ratio, each size ratio being defined as a ratio of a size of the part of original grid that is superposed on the reduced grid corresponding to the reduced pixel data to a size of the reduced grid.

Claims

1. An image processing device comprising:

an original image data acquiring unit that is configured to acquire original image data indicative of an original image, the original image data including a plurality of sets of original pixel data, the original image having a first resolution, the original image having a first size, the original image being divided into a plurality of original grids, each original grid corresponding to a set of original pixel data,

a reducing unit that is configured to create reduced image data by performing a reduction process on the original image data, the reduced image data including a plurality of sets of reduced pixel data, the reduced image data being indicative of a reduced image, the reduced image having a second resolution lower than the first resolution, the reduced image having a second size same as the first size, the reduced image being divided into a plurality of reduced grids, each reduced grid corresponding to a set of reduced pixel data, the reducing unit including;

an acquiring unit that is configured to acquire, for each set of reduced pixel data, at least one set of original pixel data satisfying a following condition that the at least one set of original pixel data corresponds to the original grid whose part is superposed on the reduced grid corresponding to the each set of reduced pixel data when the reduced image is partially superposed on the original image such that the reduced image is shifted, from a original position at which the reduced image is entirely superposed on the original image, by a prescribed length shorter than a length of one original grid; and

a reduced pixel data producing unit that is configured to produce the reduced pixel data by calculating a weighted average of the at least one set of original pixel data acquired by the acquiring unit based on size ratio, each size ratio being defined as a ratio of a size of the part of original grid that is superposed on the reduced grid corresponding to the reduced pixel data to a size of the reduced grid.

2. The image processing device according to claim 1, wherein the first resolution is an integer multiple of the second resolution.

3. The image processing device according to claim 1, further comprising a transmitting unit that is configured to transmit the reduced image data to an image forming unit, the image forming unit forming the reduced image on a recording medium based on the reduced image data by ejecting ink droplets while reciprocating a recording head in a main scanning direction, the recording head moving relative to the recording medium in a sub-scanning direction orthogonal to the main scanning direction, the original image and the reduced image extending in a first direction and a second direction, the first direction corresponding to the main-scanning direction, the second direction corresponding to the sub-scanning direction,

wherein the acquiring unit acquires at least one set of original pixel data for a set of reduced pixel data, the at least one set of original pixel data corresponding to the original grid whose part is superposed on the reduced grid corresponding to the set of reduced pixel data when the reduced image is partially superposed on the original image such that the reduced image is shifted from the original position in the second direction by the prescribed length.

4. The image processing device according to claim 3, wherein the acquiring unit acquires at least one set of original pixel data for a set of reduced pixel data, the at least one set of original pixel data corresponding to the original grid whose part is superposed on the reduced grid corresponding to the set of reduced pixel data when the reduced image is partially superposed on the original image such that the reduced image is shifted from the original position in the first direction.

5. The image processing device according to claim 3, wherein the plurality of sets of original pixel data are divided into a plurality of sets of line data having a first line data, the plurality of sets of line data indicating a plurality of line that are arranged in the second direction, each set of line data including first original pixel data and last original pixel data, the first original pixel data indicating a first original pixel, the last original pixel data indicating a last original pixel, the first original pixel and the second original pixel being arranged in the first direction, the first original pixel and the last original pixel corresponding to a first original grid an a last original grid,

wherein the reducing unit produces the reduced image data by sequentially performing the reduction process on the original pixel data from the first original pixel data to the last original pixel data, and

wherein the acquiring unit acquires at least one set of original pixel data for a set of reduced pixel data, the at least one set of original pixel data corresponding to the original grid whose part is superposed on the reduced grid corresponding to the set of reduced pixel data when the reduced image is partially superposed on the original image such that the reduced image is shifted in the second direction defined from the last original grid to the first original grid.

6. The image processing device according to claim 1, further comprising a transmitting unit that is configured to transmit the reduced image data to an image forming unit, the image forming unit forming the reduced image on a recording medium based on the reduced image data by ejecting ink droplets while reciprocating a recording head in a main scanning direction, the recording head moving relative to the recording medium in a sub-scanning direction orthogonal to the main scanning direction, the original image and the reduced image extending in a first direction and a second direction, the first direction corresponding to the main-scanning direction, the second direction corresponding to the sub-scanning direction,

wherein the second resolution indicates a resolution of the reduced image in one of the first direction and the second direction, the first resolution indicating a resolution of the original image in the one of the first direction and the second direction;

wherein the acquiring unit acquires at least one set of original pixel data for a set of reduced pixel data, the at least one set of original pixel data corresponding to the original grid whose part is superposed on the reduced grid corresponding to the set of reduced pixel data when the reduced image is partially superposed on the original image such that the reduced image is shifted in the one of the first direction and the second direction.

7. The image processing device according to claim 1, wherein the reduced image has a region that is not superposed on the original image,

wherein the reducing unit further includes a supplement grid allocating unit that is configured to allocate at least one supplement grid to the region, each supplement grid having a size same as the first size, the supplement grid corresponding to a prescribed value, the supplement grid allocating unit setting the prescribed value corresponding each supplement grid as the original pixel data.

8. The image processing device according to claim 7, wherein the prescribed value is zero.

9. The image processing device according to claim 7, wherein the supplement grid allocating unit determines the prescribed value based on the original pixel data corresponding to the original image.

10. The image processing device according to claim 7, wherein the supplement grid allocating unit determines, for each of the at least one supplement grid, the original pixel data corresponding to an original grid that is adjacent to the each of the at least one supplement grid as the prescribed value.

11. An image processing method comprising:

acquiring original image data indicative of an original image, the original image data including a plurality of sets of original pixel data, the original image having a first resolution, the original image having a first size, the original image being divided into a plurality of original grids, each original grid corresponding to a set of original pixel data,

creating reduced image data by performing a reduction process on the original image data, the reduced image data including a plurality of sets of reduced pixel data, the reduced image data being indicative of a reduced image, the reduced image having a second resolution lower than the first resolution, the reduced image having a second size same as the first size, the reduced image being divided into a plurality of reduced grids, each reduced grid corresponding to a set of reduced pixel data, the creating step including;

acquiring, for each set of reduced pixel data, at least one set of original pixel data satisfying a following condition that the at least one set of original pixel data corresponds to the original grid whose part is superposed on the reduced grid corresponding to the each set of reduced pixel data when the reduced image is partially superposed on the original image such that the reduced image is shifted, from a original position at which the reduced image is entirely superposed on the original image, by a prescribed length shorter than a length of one original grid; and

producing the reduced pixel data by calculating a weighted average of the at least one set of original pixel data acquired in the acquiring step based on size ratio, each size ratio being defined as a ratio of a size of the part of original grid that is superposed on the reduced grid corresponding to the reduced pixel data to a size of the reduced grid.

12. A non-transitory computer readable storage medium storing a set of program instructions installed on and executed by an image processing device, the program instructions comprising:

acquiring original image data indicative of an original image, the original image data including a plurality of sets of original pixel data, the original image having a first resolution, the original image having a first size, the original image being divided into a plurality of original grids, each original grid corresponding to a set of original pixel data,

creating reduced image data by performing a reduction process on the original image data, the reduced image data including a plurality of sets of reduced pixel data, the reduced image data being indicative of a reduced image, the reduced image having a second resolution lower than the first resolution, the reduced image having a second size same as the first size, the reduced image being divided into a plurality of reduced grids, each reduced grid corresponding to a set of reduced pixel data, the creating step including;

acquiring, for each set of reduced pixel data, at least one set of original pixel data satisfying a following condition that the at least one set of original pixel data corresponds to the original grid whose part is superposed on the reduced grid corresponding to the each set of reduced pixel data when the reduced image is partially superposed on the original image such that the reduced image is shifted, from a original position at which the reduced image is entirely superposed on the original image, by a prescribed length shorter than a length of one original grid; and

producing the reduced pixel data by calculating a weighted average of the at least one set of original pixel data acquired in the acquiring step based on size ratio, each size ratio being defined as a ratio of a size of the part of original grid that is superposed on the reduced grid corresponding to the reduced pixel data to a size of the reduced grid.