| 摘要 |
PURPOSE: To make possible perceptual encoding of an image by determining a unperceptive quantization noise quantity regarding one parameter or more among a frequency, a contrast, and a texture. CONSTITUTION: To give each pixel one piece of data regarding a contrast and lightness, one of inputs to a model 28 is sent out of a processor 21. Then this perceptual shield model 28 gives an estimated value of a quantity of encoding distortion added to each pixel of each divided band signal so as to eliminate a difference in recognition between a source image and an encoded image. This model makes good use of several known properties of a human visual system(HVS) by a unique method. Namely, the properties in use are frequency response, sensitivity of contrast, and shielding property of texture in this case. Then this model does not intends the complete description of the HVS, but gives an approximation of the influence of the HVS on the perception of an image given to a specific analyzing/composing means. |
