图像灰度级拉伸算法
image gray-lever stretch algorithm
灰度级图像水印
Gray-level Image Watermarking
灰度级水印
grey-level watermarking
Gray level digital image watermarking
gray-scale watermark
灰度级等距离拉伸
gray-level in equal distance
灰度级－彩色变换法
gray-color transform technique
二维灰度级直方图
two-dimensional gray-level histogram
two-dimensional gray level histogram