Image enhancement device

• US 20060222255A1
• Filed: 03/23/2006
• Published: 10/05/2006
• Est. Priority Date: 03/29/2005
• Status: Active Grant

• Current Assignee: Megachips Corporation
• Original Assignee: Megachips LSI Solutions Incorporated (Megachips Corporation)
• Inventors: Mizuno, Yusuke, Nara, Yusuke
• Granted Patent: US 8,050,506 B2
• Time in Patent Office: Days
• US Class Current: 382/240
• CPC Class Codes: H04N 19/115 Selection of the code volume for a coding unit prior to coding
• CPC Class Codes: H04N 19/124 Quantisation
• CPC Class Codes: H04N 19/146 Data rate or code amount at the encoder output
• CPC Class Codes: H04N 19/17 the unit being an image region, e.g. an object
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/63 using sub-band based transform, e.g. wavelets
• CPC Class Codes: H04N 19/645 by grouping of coefficients into blocks after the transform
• CPC Class Codes: H04N 19/647 using significance based coding, e.g. Embedded Zerotrees of Wavelets [EZW] or Set Partitioning in Hierarchical Trees [SPIHT]

Abstract

An image enhancement device is obtained which is capable of extracting, as regions of interest, still objects or objects with smaller motion vectors, or regions located out of the central area of an image. An image processing module (22) applies memorized-color correction to image data, and then stores, in an SDRAM (7) through a memory interface (26), information about the positions of the memorized-color-corrected pixels and information about the application levels (correction levels) applied to the memorized-color-corrected pixels. A mask signal generating module (23) refers to the positional information stored in the SDRAM (7) to extract the memorized-color-corrected regions of the image data as regions of interest. Also, the mask signal generating module (23) refers to the information about the correction levels stored in the SDRAM (7) to set priorities of the regions of interest in such a way that higher priorities are assigned to regions of interest that are memorized-color-corrected at higher levels (i.e., with larger amounts of correction).

Claims

1. An image enhancement device, comprising:

a region-of-interest extracting block that extracts a plurality of regions of interest from input image data;

a priority setting block that sets priorities respectively to said regions of interest; and

a code rate control block that controls a code rate in such a way that larger amounts of code are assigned to said regions of interest having higher ones of said priorities.

2. The image enhancement device according to claim 1, wherein said region-of-interest extracting block extracts said regions of interest by extracting at least one of a particular color and a particular object from said image data.

3. The image enhancement device according to claim 2, further comprising an image processing block that applies a memorized-color correction to said image data,

wherein said region-of-interest extracting block extracts, as said regions of interest, regions in said image data that are subjected to said memorized-color correction, and

said priority setting block sets said priorities in such a way that higher ones of said priorities are assigned to said regions of interest that are subjected to said memorized-color correction at higher application levels.

4. The image enhancement device according to claim 2, further comprising an image processing block that applies an edge emphasis process to said image data,

wherein said region-of-interest extracting block extracts, as said regions of interest, regions in said image data that are subjected to said edge emphasis process, and

said priority setting block sets said priorities in such a way that higher ones of said priorities are assigned to said regions of interest that are subjected to said edge emphasis process at higher application levels.

5. The image enhancement device according to claim 2, further comprising an image processing block that applies a noise reduction process to said image data,

wherein said region-of-interest extracting block extracts, as regions of no-interest, regions in said image data that are subjected to said noise reduction process.

6. The image enhancement device according to claim 2, wherein said image data is data about an image taken by a camera that is capable of selecting an image mode, and

said region-of-interest extracting block extracts, as said regions of interest, at least one of said particular color and said particular object that is previously determined for each said image mode.

7. The image enhancement device according to claim 1, further comprising a wavelet transform block that recursively band-divides said image data into a high-band component and a low-band component through a wavelet transform, so as to generate a plurality of sub-bands having different resolutions,

wherein said image data is data about an image taken by a camera that has a preview function and an image storing fiction, and

for a preview, said code rate control block applies said amount-of-code assignment control only to a first sub-band having a resolution necessary for the preview, and

for storing of an image, said code rate control block applies said amount-of-code assignment control to a second sub-band having a higher resolution than said first sub-band.

8. The image enhancement device according to claim 7,

wherein said camera has a function of selecting a data size of an image to be stored when storing an image, and

for the storing of an image, said code rate control block applies said amount-of-code assignment control only to said second sub-band that corresponds to said selected data size.