Information processing apparatus, image forming system, and information processing method relating to an image compression

Patent metadata

Field	Value
Publication number	US-2016112718-A1
Application number	US-201514877163-A
Country	US
Kind code	A1
Filing date	Oct 7, 2015
Priority date	Oct 16, 2014
Publication date	Apr 21, 2016
Grant date	—

Abstract

An information processing apparatus having a compression unit configured to compress image data and to store compressed image data in a storage unit, a determination unit configured to determine a compression method on a basis of a data size of the compressed image data stored in the storage unit, a decompression unit configured to decompress the compressed image data stored in the storage unit, and a transmission unit configured to transmit image data decompressed by the decompression unit and information on the determined compression method to an image forming apparatus.

First claim

What is claimed is:

1 . An information processing apparatus comprising:
a compression unit configured to compress image data and to store compressed image data in a storage unit; a determination unit configured to determine a compression method on a basis of a data size of the compressed image data stored in the storage unit; a decompression unit configured to decompress the compressed image data stored in the storage unit; and a transmission unit configured to transmit image data decompressed by the decompression unit and information on the determined compression method to an image forming apparatus.

2 . The information processing apparatus according to claim 1 , wherein the determination unit is configured to determine, after the compression, whether the data size of the compressed image data in the storage unit is greater than a threshold value, and to determine the compression method in accordance with a result of the determination.

3 . The information processing apparatus according to claim 2 , wherein
the threshold value is determined in accordance with the size of a buffer for storing received image data on a memory included in the image forming apparatus.

4 . The information processing apparatus according to claim 2 , wherein
the compression method determined in accordance with the results of the determination includes lossless compression and lossy compression, and the determination unit:
determines the compression method to be lossy compression in a case where it is determined that the data size of the compressed image data is greater than the threshold value; and
determines the compression method to be lossless compression in a case where it is determined that the data size of the compressed image data is not greater than the threshold value.

5 . The information processing apparatus according to claim 4 , wherein
the lossy compression includes two kinds of compression methods with different compression ratios, and the determination unit determines one of the two kinds of compression methods with different compression ratios by using another threshold value greater than the threshold value in a case where the compression method is determined to be lossy compression.

6 . The information processing apparatus according to claim 5 , wherein
Of the two kinds of compression methods, the compression method with a higher compression ratio is a method in which compression methods with different contents are applied in accordance with an area of an image, and the transmission unit transmits attribute information for specifying the area to the image forming apparatus along with decompressed image data.

7 . The information processing apparatus according to claim 3 , wherein
the size of the buffer in the image forming apparatus differs depending on the size of a printing medium that is used for printing based on received image data, and the transmission unit further transmits information on the size of the printing medium to the image forming apparatus.

8 . The information processing apparatus according to claim 4 , wherein
the compression method of image data in the information processing apparatus is lossless compression and the contents of the lossless compression are different from the contents of lossless compression that may be determined by the determination unit.

9 . The information processing apparatus according to claim 8 , wherein
the lossless compression that may be determined by the determination unit is a compression method for encoding a predicted error by using the Golomb-Rice coding, and the lossless compression, which is the compression method of image data in the information processing apparatus, is a compression method that uses the Golomb-Rice coding and whose compression efficiency of encoding has been increased.

10 . The information processing apparatus according to claim 1 , wherein
in a case where the same image data is transmitted to the image forming apparatus a plurality of times, in the second and subsequent transmissions, the information on the compression method determined for the image data at the time of the first transmission is transmitted.

11 . An image forming system including an information processing apparatus and an image forming apparatus connected with the information processing apparatus, wherein
the information processing apparatus comprises:
a first compression unit configured to compress image data and to store compressed image data in a first storage unit;
a first determination unit configured to determine information to be used to determine a compression method on a basis of a data size of the compressed image data stored in the first storage unit;
a decompression unit configured to decompress the compressed image data stored in the first storage unit; and
a transmission unit configured to transmit image data decompressed by the decompression unit and the information determined by the first determination unit to an image forming apparatus, and
the image forming apparatus comprises:
a second determination unit configured to acquire the information transmitted by the information processing apparatus, and to determine, on a basis of the acquired information, a compression method for compressing image data;
a second compression unit configured to acquire the image data transmitted by the information processing apparatus, and to compress the acquired image data according to the second determined compression method to store the compressed image data in a second storage unit; and
an image forming unit configured to form an image on a basis of the compressed image data stored in the second storage unit.

12 . The image forming system according to claim 11 , wherein the first determination unit of the information processing unit is configured to determine a compression method on the basis of the data size of the compressed image data stored in the first storage unit, and determine the information, which is indicates the determined compression method.

13 . The image forming system according to claim 12 , wherein the first determination unit is configured to determine, after the first compression, whether the data size of the compressed image data in the storage unit is greater than a threshold value, and to determine the compression method in accordance with a result of the determination.

14 . The image forming system according to claim 11 , wherein the image forming apparatus is further comprises:
a third determination unit configured to determine whether or not the storing into the second storage unit is successful; and a request unit configured to require the information processing unit to re-transmit the image data decompressed by the decompressed unit, and wherein the second compression unit of the image forming unit is further configured to acquire the image data re-transmitted by the information processing apparatus, and to compress the acquired image data according to a lossy compression method to store the lossy-compressed image data in the second storage unit.

15 . The image forming system according to claim 11 , wherein the image forming apparatus is further comprises:
a third determination unit configured to determine whether or not the storing into the second storage unit is successful; and a request unit configured to require the information processing unit to re-transmit the image data decompressed by the decompressed unit, and wherein the second compression unit of the image forming unit is further configured to acquire the image data re-transmitted by the information processing apparatus,

Assignees

• Canon Kk

Inventors

• Sakata Munetaka

Classifications

• H04N19/15

  by monitoring actual compressed data size at the memory before deciding storage at the transmission buffer · CPC title

• H04N1/2104

  for one or a few pictures · CPC title

• G06K15/181

  Receiving print data characterized by its formatting, e.g. particular page description languages · CPC title

• H04N19/12

  Selection from among a plurality of transforms or standards, e.g. selection between discrete cosine transform [DCT] and sub-band transform or selection between H.263 and H.264 · CPC title

• H04N19/61

  in combination with predictive coding · CPC title