초록 ▼

A method of hiding a first image in a second image to produce a combined image includes the steps of: a) modifying the first image according to the content of the second image, so that when the modified first image is added to the second image to produce the combined image, no visible differences wi

A method of hiding a first image in a second image to produce a combined image includes the steps of: a) modifying the first image according to the content of the second image, so that when the modified first image is added to the second image to produce the combined image, no visible differences will exist between the second image and the combined image; and b) adding the modified first image to the second image to produce the combined image.

대표청구항 ▼

[ What is claimed is:] [4.] A method of hiding a first image in a second image to produce a combined image, comprising the steps of:a) modifying the first image according to the content of the second image, so that when the modified first image is added to the second image to produce the combined im

[ What is claimed is:] [4.] A method of hiding a first image in a second image to produce a combined image, comprising the steps of:a) modifying the first image according to the content of the second image, so that when the modified first image is added to the second image to produce the combined image, no visible differences will exist between the second image and the combined image, wherein the step of modifying the first image comprises the steps of:I) modifying the first and second images according to a display model having a tone scale response, clipping, MTF, and quantization components representing a display medium for displaying the combined image;ii) further modifying the first and second images according to a human visual system model having a cone nonlinearity function, a contrast sensitivity function, and a set of spatial frequency filters representing spatial dependencies of a visual system to produce a first and second set of filtered images;iii) employing the second set of spatial filtered images to determine a set of masking images representing the maximum possible distortions that can be added to the second image without being visible;iv) employing the set of masking images to attenuate the contrast of the corresponding images in the first set of spatial filtered images to produce a set of contrast attenuated spatial filtered images; andv) accumulating the contrast attenuated spatial filtered images to produce the modified first image;vi) further modifying the modified image by the inverse of the contrast sensitivity function; andb) adding the modified first image to the second image to produce the combined image, wherein the step of adding the modified first image to the second image further comprises the steps of:I) modifying the second image by the display model tone scale response and MTF and cone nonlinearity function;ii) summing the modified first image with the modified second image to produce a combined image; andiii) further modifying the combined image by the inverse of the cone nonlinearity.