Method and apparatus for visual lossless image syntactic encoding

A method of generating visual perception thresholds for image processing, the method comprising:

• analyzing details of frames of a video signal;
• estimating parameters of said details;
• and
• defining a visual perception threshold for each of said details in accordance with said estimated detail parameters,
• wherein said estimating comprises at least one of the following:
• determining a per-pixel signal intensity change between a current frame and a previous frame, normalized by a maximum intensity;
• determining a normalized volume of intraframe change by high frequency filtering of said frame, summing the intensities of said filtered frame and normalizing the resultant sum by the maximum possible amount of information within a frame;
• generating a volume of inter-frame changes between a current frame and its previous frame normalized by said maximum possible amount of information volume within a frame;
• generating a normalized volume of inter-frame changes for a group of pictures from the output of said previous step of generating;
• evaluating a signal-to-noise ratio by high pass filtering a difference frame between said current frame and its said previous frame by selecting those intensities of said difference frame lower than a threshold defined as three times a noise level under which noise intensities are not perceptible to the human eye, summing the intensities of the pixels in the filtered frame and normalizing said sum by said maximum intensity and by the total number of pixels in a frame;
• generating a normalized intensity value per-pixel;
• generating a per-pixel color saturation level;
• generating a per-pixel hue value;
• and
• determining a per-pixel response to said hue value.

A method for describing an image, the method comprising

• determining which details in said image can be distinguished by the human eye and which ones can only be detected by it;
• providing one bit to describe a pixel which can only be detected by the human eye;
• and
• providing three bits to describe a pixel which can be distinguished by the human eye.