Encoding device using parallelized encoding, decoding device using parallelized decoding, and image forming device, method, and program storage medium including the same

1. An encoding device comprising:

a first memory that stores image data;

a plurality of second memories that are associated with a plurality of target pixels in the image data, each second memory storing pixel data of one or more reference pixels near the associated target pixel thereof;

a controller that causes each second memory to store pixel data of the one or more reference pixels near the associated target pixel thereof specified from the image data stored in the first memory; and

a plurality of encoders that perform encoding on each of the plurality of target pixels by estimating pixel data of each target pixel using pixel data of the one or more reference pixels near each respective target pixel stored in the plurality of second memories;

wherein the plurality of target pixels have different positions in a subscanning direction such that one target pixel does not overlap with another target pixel in a main scanning direction, and storage capacity sufficient for pixel data of all of the reference pixels used by the plurality of encoders is equal to or less than storage capacity sufficient for one line of image data stored in the first memory.

2. The encoding device of claim 1 , further comprising a plurality of speed adjusting units provided in correspondence with respective encoders of the plurality of encoders that adjust the number of pixels encoded by each of the encoders to the number of pixels encoded by the encoder that encodes the smallest number of pixels, from respective numbers of pixels encoded by each of the respective plurality of encoders within a given duration.

3. An image forming device comprising at least the encoding device of claim 2 .

4. The image forming device according to claim 3 , further comprising a decoding device comprising:

a first memory that stores encoded image data;

a plurality of second memories associated with a plurality of target pixels in the image data, each second memory storing pixel data of one or more reference pixels near the associated target pixel thereof;

a controller that causes each second memory to store pixel data of the one or more reference pixels near the associated target pixel thereof specified from the image data stored in the first memory; and

a plurality of decoders that perform decoding on each of the plurality of target pixels by estimating pixel data of each target pixel using pixel data of the one or more reference pixels near each respective target pixel stored in the plurality of second memories,

wherein the plurality of target pixels have different positions in a subscanning direction such that one target pixel does not overlap with another target pixel in a main scanning direction, and storage capacity sufficient for pixel data of all of the reference pixels used by the plurality of decoders is equal to or less than storage capacity sufficient for one line of image data stored in the first memory.

5. The image forming device of claim 4 , wherein the decoding device further comprises a plurality of speed adjusting units provided in correspondence with respective decoders of the plurality of decoders that adjust the number of pixels decoded by each of the decoders to the number of pixels decoded by the decoder that decodes the smallest number of pixels, from respective numbers of pixels decoded by each of the respective plurality of decoders within a given duration.

6. An image forming device comprising at least the encoding device of claim 1 .

7. The image forming device according to claim 6 , further comprising a decoding device comprising:

a first memory that stores encoded image data;

a plurality of second memories associated with a plurality of target pixels in the image data, each second memory storing pixel data of one or more reference pixels near the associated target pixel thereof;

a controller that causes each second memory to store pixel data of the one or more reference pixels near the associated target pixel thereof specified from the image data stored in the first memory; and

a plurality of decoders that perform decoding on each of the plurality of target pixels by estimating pixel data of each target pixel using pixel data of the one or more reference pixels near each respective target pixel stored in the plurality of second memories,

wherein the plurality of target pixels have different positions in a subscanning direction such that one target pixel does not overlap with another target pixel in a main scanning direction, and storage capacity sufficient for pixel data of all of the reference pixels used by the plurality of decoders is equal to or less than storage capacity sufficient for one line of image data stored in the first memory.

8. The image forming device of claim 7 , wherein the decoding device further comprises a plurality of speed adjusting units provided in correspondence with respective decoders of the plurality of decoders that adjust the number of pixels decoded by each of the decoders to the number of pixels decoded by the decoder that decodes the smallest number of pixels, from respective numbers of pixels decoded by each of the respective plurality of decoders within a given duration.

9. A decoding device comprising:

a first memory that stores encoded image data;

a plurality of second memories associated with a plurality of target pixels in the image data, each second memory storing pixel data of one or more reference pixels near the associated target pixel thereof;

a controller that causes each second memory to store pixel data of the one or more reference pixels near the associated target pixel thereof specified from the image data stored in the first memory; and

a plurality of decoders that perform decoding on each of the plurality of target pixels by estimating pixel data of each target pixel using pixel data of the one or more reference pixels near each respective target pixel stored in the plurality of second memories,

wherein the plurality of target pixels have different positions in a subscanning direction such that one target pixel does not overlap with another target pixel in a main scanning direction, and storage capacity sufficient for pixel data of all of the reference pixels used by the plurality of decoders is equal to or less than storage capacity sufficient for one line of image data stored in the first memory.

10. The decoding device of claim 9 , further comprising a plurality of speed adjusting units provided in correspondence with respective decoders of the plurality of decoders that adjust the number of pixels decoded by each of the decoders to the number of pixels decoded by the decoder that decodes the smallest number of pixels, from respective numbers of pixels decoded by each of the respective plurality of decoders within a given duration.

11. An image forming device comprising at least the decoding device of claim 10 .

12. An image forming device comprising at least the decoding device of claim 9 .

13. The image forming device of claim 12 , further comprising a plurality of speed adjusting units provided in correspondence with respective decoders of the plurality of decoders that adjust the number of pixels decoded by each of the decoders to the number of pixels decoded by the decoder that decodes the smallest number of pixels, from respective numbers of pixels decoded by each of the respective plurality of decoders within a given duration.

14. A computer readable storage medium storing a computer program that causes a computer to execute an encoding process, the process comprising:

storing image data;

storing pixel data of one or more reference pixels near each of a plurality of target pixels in the image data; and

encoding the respective target pixels by estimating pixel data of the target pixels in the image data, using pixel data of the one or more reference pixels near each respective target pixel,

wherein the plurality of target pixels have different positions in a subscanning direction such that one target pixel does not overlap with another target pixel in a main scanning direction, and storage capacity sufficient for pixel data of all of the reference pixels is equal to or less than storage capacity sufficient for one line of image data.

15. A computer readable storage medium storing a computer program that causes a computer to execute a decoding process, the process comprising:

storing pixel data of one or more reference pixels near each of a plurality of target pixels in image data from encoded image data;

storing image data of the one or more reference pixels near each respective target pixels; and

decoding the respective target pixels by estimating pixel data of the target pixels in the image data using pixel data of the one or more reference pixels near each respective target pixel,

wherein the plurality of target pixels have different positions in a subscanning direction such that one target pixel does not overlap with another target pixel in a main scanning direction, and storage capacity sufficient for pixel data of each of the reference pixels is equal to or less than storage capacity sufficient for one line of image data.

16. An encoding method comprising:

storing image data;

storing pixel data of one or more reference pixels near each of a plurality of target pixels in the image data; and

encoding the respective target pixels by estimating pixel data of the target pixels in the image data, using pixel data of the one or more reference pixels near each respective target pixel,

wherein the plurality of target pixels have different positions in a subscanning direction such that one target pixel does not overlap with another target pixel in a main scanning direction, and storage capacity sufficient for pixel data of all of the reference pixels is equal to or less than storage capacity sufficient for one line of image data.

17. A decoding method comprising:

storing pixel data of one or more reference pixels near each of a plurality of target pixels in encoded image data;

storing the pixel data of the one or more reference pixels near each respective target pixel; and

decoding the respective target pixels by estimating pixel data of the target pixels in the image data using pixel data of the one or more reference pixels near each respective target pixel,

wherein the plurality of target pixels have different positions in a subscanning direction such that one target pixel does not overlap with another target pixel in a main scanning direction, and storage capacity sufficient for pixel data of each of the reference pixels is equal to or less than storage capacity sufficient for one line of image data.