Method and apparatus for visual lossless image syntactic encoding
DCFirst Claim
1. A visual perception threshold unit for image processing, the threshold unit comprising:
- a parameter generator to generate a multiplicity of parameters that describe at least some of the information content of at least one video frame to be processed; and
a threshold generator to generate from said parameters, a plurality of visual perception threshold levels to be associated with the pixels of the at least one video frame, wherein said threshold levels define contrast levels above which a human eye can distinguish a pixel from among its neighboring pixels of said at least one video frame.
4 Assignments
Litigations
0 Petitions
Accused Products
Abstract
A visual perception threshold unit for image processing identifies a plurality of visual perception threshold levels to be associated with the pixels of a video frame, wherein the threshold levels define contrast levels above which a human eye can distinguish a pixel from among its neighboring pixels of the video frame. The present invention also includes a method of generating visual perception thresholds by analysis of the details of the video frames, estimating the parameters of the details, and defining a visual perception threshold for each detail in accordance with the estimated detail parameters. The present invention further includes a method of describing images by determining which details in the image can be distinguished by the human eye and which ones can only be detected by it.
132 Citations
31 Claims
-
1. A visual perception threshold unit for image processing, the threshold unit comprising:
-
a parameter generator to generate a multiplicity of parameters that describe at least some of the information content of at least one video frame to be processed; and
a threshold generator to generate from said parameters, a plurality of visual perception threshold levels to be associated with the pixels of the at least one video frame, wherein said threshold levels define contrast levels above which a human eye can distinguish a pixel from among its neighboring pixels of said at least one video frame. - View Dependent Claims (2, 29, 30, 31)
-
-
3. A method of generating visual perception thresholds for image processing implemented by one or more elements of a video encoding device, 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 current frame, summing the intensities of said filtered frame and normalizing the resultant sum by the a maximum possible amount of information within a frame;
generating a volume of inter-frame changes between a said current frame and its said 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 frames 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 difference frame and normalizing said sum by said maximum intensity and by the a 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.
-
-
4. A method for describing an image implemeneted by one or more elements of a video encoding device, 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.
-
-
5. A video compression system comprising:
-
a parameter generator to generate one or more parameters that describe information content of a video frame; and
a threshold generator to generate, from at least one of the parameters, a plurality of visual perception threshold levels to be associated with pixels of the video frame, wherein said threshold levels define contrast levels above which a pixel of the video frame can be visually distinguished from its neighboring pixels of the video frame. - View Dependent Claims (6, 7, 8, 9)
-
-
10. A video encoder comprising:
-
a parameter generator to generate multiple parameters that describe information content of a video frame; and
a threshold generator to generate, from at least one of the multiple parameters, a plurality of visual perception threshold levels to be associated with pixels of the video frame, wherein said threshold levels define contrast levels above which a pixel of the video frame can be visually distinguished from its neighboring pixels of the video frame. - View Dependent Claims (11, 12, 13, 14, 15)
-
-
16. A system comprising:
-
means for generating one or more parameters that describe information content of a video frame; and
means for generating, from at least one of the parameters, a plurality of visual perception threshold levels to be associated with pixels of the video frame, wherein said threshold levels define contrast levels above which a pixel of the video frame can be visually distinguished from its neighboring pixels of the video frame. - View Dependent Claims (17, 18)
-
-
19. A video compression system comprising:
-
means for analyzing one or more details associated with one or more frames of a video signal;
means for estimating parameters of individual analyzed details; and
means for defining a visual perception threshold for individual analyzed details in accordance with at least one of the estimated parameters, wherein said means for estimating comprises at least one of;
means for determining a per-pixel signal intensity change between a current frame and a previous frame, normalized by a maximum intensity;
means for determining a normalized volume of intraframe change by high frequency filtering of said current frame, summing the intensities of said filtered frame and normalizing the resultant sum by a maximum possible amount of information within a frame;
means for generating a volume of inter-frame changes between said current frame and said previous frame normalized by said maximum possible amount of information within a frame;
means for generating a normalized volume of inter-frame changes within a group of frames normalized by said maximum possible amount of information within a frame and by a number of frames comprising said group of frames;
means for evaluating a signal-to-noise ratio by high pass filtering a difference frame between said current frame and said previous frame by selecting intensities of said difference frame lower than a threshold defined as three times a noise level under which noise intensities are not visually perceptible, summing the intensities of pixels in the filtered difference frame and normalizing said sum by said maximum intensity and by the total number of pixels in a frame;
means for generating a normalized intensity value per-pixel;
means for generating a per-pixel color saturation level;
means for generating a per-pixel hue value;
ormeans for determining a per-pixel response to said hue value. - View Dependent Claims (20)
-
-
21. A method implemented by one or more elements of a video encoding device comprising:
-
identifying one or more distinguishable details in an image, individual distinguishable details being associated with a contrast level at which a pixel can be visually distinguished from among its neighboring pixels;
using a plurality of bits to describe individual identified distinguishable details; and
using less than said plurality of bits to describe one or more individual details in the image not identified as distinguishable. - View Dependent Claims (22, 23, 24)
-
-
25. A system comprising:
-
means for identifying one or more distinguishable details in an image, individual distinguishable details being associated with a contrast level at which a pixel can be visually distinguished from among its neighboring pixels;
means for using a plurality of bits to describe individual identified distinguishable details; and
means for using less than said plurality of bits to describe one or more individual details in the image not identified as distinguishable. - View Dependent Claims (26, 27, 28)
-
Specification