发明公开
- 专利标题: Method and apparatus for processing image data
- 专利标题(中): 用于处理图像数据的方法和装置
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申请号: EP86100035.4申请日: 1986-01-02
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公开(公告)号: EP0188193A3公开(公告)日: 1989-04-19
- 发明人: Pennebaker, William Boone , Mitchell, Joan La Verne
- 申请人: International Business Machines Corporation
- 申请人地址: Old Orchard Road Armonk, N.Y. 10504 US
- 专利权人: International Business Machines Corporation
- 当前专利权人: International Business Machines Corporation
- 当前专利权人地址: Old Orchard Road Armonk, N.Y. 10504 US
- 代理机构: Ahlman, Bertel
- 优先权: US692007 19850115
- 主分类号: H04N1/40
- IPC分类号: H04N1/40
摘要:
A method and apparatus for processing images using gray scale techniques includes means (40) for obtaining a histogram of levels in an image; means (42) for analyzing said histogram to identify one or more ranges of background in said image; means (44, 48, 52) for converting each of said ranges of background to a constant value to achieve flat backgrounds in said image; means for generating a dynamic range expansion table for each image; means for correcting said image data for dynamic range compression due to coring during processing of said image data by reference to said dynamic range expansion table. The process may also include means for encoding (54) said processed image using gray scale encoding techniques, means (46) for filtering all nonbackground pixels in said image, means for generating for said image a shading correction for each pixel in said image; means for correcting each pixel for shading employing said shading correction generated for each pixel, means for determining if said image is a graphics image; means for generating a dynamic range expansion table for each graphics image; means for correcting said image data for dynamic range compression by reference to said dynamic range expansion table, means for creating a second table of values from parameters contained in said encoded image data; and means for translating decoded image pixel values by reference to said second table to correct for quantization noise.
公开/授权文献
- EP0188193A2 Method and apparatus for processing image data 公开/授权日:1986-07-23
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