摘要
将灰度图像的查找表逆半调算法扩展到彩色图像的逆半调,虽然考虑了彩色图像中三通道的色彩相关性,但简单地以半调值为索引值向映射表中添加连续值,不仅使映射表中的数据不够真实,也使得逆半调图像质量受半调噪声影响而降低。为此,提出一种色彩分类存储的查找表彩色图像逆半调方法,它首先从连续图到半调图对像素值进行色彩配比,然后判断配比值:若两值的色彩配比值相等或相近,则以半调值为索引,将连续值存入查找映射表中;若不相近,则将该值存入一个替补表中,作为查找表估值的依据。实验证明,色彩分类的查找表图像逆半调效果图的视觉效果比查找表彩色图像逆半调效果图的好,且其峰值信噪比、色彩还原程度、色彩倾向值均高于查找表方法所得值。
The inverse halftone algorithm of gray image with Loop-Up Table is extended to the color images, though the correlation of three-channel in color images is considered, with the halftone value as the index value to add continuous value to the mapping table simply, not only makes the data in the map not true, but also makes the inverse halftone image quality influenced by the halftone noise and reduces the quality. Therefore, puts forward a kind of Look-Up Table color image inverse halftone algorithm with color block storage. The method first matches the color value of pixel between continuous image and halftone image, then determines the match ratio. If the match ratio is equal or similar, saves the continuous value into the look-up map with the half tone value as index; if not similar, stores the continuous value in a substitute table, as a basis of the estimation of look-up table. Experiments show that the visual effect of image inverse halftone Look-Up Table with color block storage is better than that of color image inverse halftone of lookup table, and the signal-to-noise ratio of peak value, the degree of color reproduction and the color trend are higher than the value from the lookup table method.
出处
《湖南工业大学学报》
2013年第5期95-99,共5页
Journal of Hunan University of Technology
基金
国家自然科学基金资助项目(61170102)
湖南省自然科学基金资助项目(11JJ3070)
湖南省教育厅科研基金资助项目(12A039)
湖南工业大学研究生创新基金资助项目(CX1308)
关键词
查找表逆半调
彩色逆半调
色彩分块存储
彩色查找表
LUT inverse halftone
color Inverse halftone
color block storage
color lookup table
