Data processor for preventing block distortion for an achromatic

Facsimile and static presentation processing – Natural color facsimile – Specific image-processing circuitry

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

358515, 358518, 348642, 348645, H04N 965, H04N 968, H04N 146, G03F 308

Patent

active

055637264

ABSTRACT:
In data processing wherein image data are processed by dividing them into blocks, a chroma data W is obtained from the color difference data W.sub.R and W.sub.B, and the color difference data W.sub.R and W.sub.B are corrected according to an amplitude of the chroma data W. For example, if the chroma W is smaller than a prescribed threshold value, the color difference data W.sub.R and W.sub.B are set as zero. Then, the so-called block distortion can be prevented. The degree of the correction may depend on the amplitude of the chroma data W. On the other hand, DC coefficients of discrete cosine transform coefficients of adjacent blocks are compared with each other. When the DC coefficients are different from each other, block distortion occurs if they represent a same image. Then, if differences of DC coefficients of discrete cosine transform coefficients of adjacent blocks are small with each other, the DC coefficients are corrected to tend to have similar values. As to the AC coefficients, a comparator compares absolute values of AC components in the DCT coefficient data received from a discrete cosine transform section with a prescribed threshold value. Then, if absolute values of AC components in the DCT coefficient data are smaller than a prescribed threshold value, the values of the AC components are not sent to a coding section because in such cases read errors or the like are thought to affect the AC components.

REFERENCES:
patent: 4167750 (1979-09-01), Tomimoto et al.
patent: 4845548 (1989-07-01), Kohno et al.
patent: 4903142 (1990-02-01), Hasebe et al.
patent: 4984076 (1991-01-01), Watanabe
patent: 5031034 (1991-07-01), Shimizu et al.
patent: 5060060 (1991-10-01), Udagawa et al.
patent: 5319448 (1994-06-01), Ohki et al.
patent: 5418575 (1995-05-01), Kaneko et al.
"DCT Image Coding Using Adaptive Quantization Application To Digital Color Copiers" by Kazuyuki Murata (Gazou Denshi Gakkaishi; vol. 20, No. 5 (1991) (467).

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Data processor for preventing block distortion for an achromatic does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Data processor for preventing block distortion for an achromatic, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Data processor for preventing block distortion for an achromatic will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-61387

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.