Video compression noise immunity
View Patent ↗A method of improving run length video encoding commands is described in which all compression commands that require a current pixel value to be compared to a previously sent pixel value to determine whether compression can take place in a longer run is adjusted to relieve stringent match conditions. Instead of requiring an exact match, the compression engine subtracts one pixel value from another, and compares the absolute value of the result to a threshold value. In this way, run lengths can be lengthened for purposes of compression and compression efficiency can be increased.
1. A video code device, comprising:
an input to receive a serial stream of color pixel values; and
an encoder to store a first one of said color pixel values, and to receive a current one of said color pixel values, wherein said encoder determines whether said current one of said color pixel values exceeds said first one of said color pixel values by less than a threshold and, if so, encodes said current pixel value by color match encoding, the encoder comprising:
a threshold analyzer to receive the current one of said color pixel values; and
a video compressor in communication with the threshold analyzer to communicate to the threshold analyzer the first one of said color pixel values comprising a previously identified one of said color pixel values in the stream of color pixel values; and wherein said threshold analyzer performs color space hysteresis on said current color pixel value to determine whether said current one of said color pixel values satisfies at least one of:
(a) a predetermined positional relationship in a current or previous frame relative to said color pixel value standard, and
(b) a predetermined positional relationship in a current run of pixels that includes another pixel having said predetermined positional relationship in a current or previous frame relative to said color pixel value standard.
2. A device as in claim 1 wherein said predetermined positional relationship is a location immediately to the left of one of said current color pixel value and said another pixel.
3. A device as in claim 1 wherein said predetermined positional relationship is a location immediately above one of said current color pixel value and said another pixel.
4. A device as in claim 1 wherein said predetermined positional relationship is a common location in an immediately prior frame relative to one of said current color pixel value and said another pixel.
5. A device as in claim 1 wherein the color space hysteresis includes defining a color palette of three dimensional color spaces, and expanding said three dimensional color spaces in three dimensions to includes portions of adjacent three dimensional color spaces.
6. A device as in claim 1 wherein the color match encoding is run-length encoding.
7. A device as in claim 1 wherein the encoder stores first and second ones of said color pixel values, and
wherein said encoder determines whether said current one of said color pixel values exceeds said first color pixel value by less than a threshold and,
if so, encodes said current pixel value as a bit having a first binary state, and
if not, determines whether said current one of said color pixel values exceeds said second color pixel value by less than a threshold and,
if so, encodes said current pixel value as a bit having a second binary state different from the first binary state.
8. A device as in claim 7 wherein the encoder stores first and second sets of said color pixel component values, and
wherein said encoder determines whether each of said current ones of said color pixel component values exceeds corresponding ones of said first color pixel component values by less than a threshold and,
if so for all such color pixel component values in said current set, encodes said current pixel value as a bit having a first binary state, and
if not for any such color pixel component values in said current set, determines whether said current ones of said color pixel component values exceed corresponding ones of said second color pixel component values by less than a threshold and,
if so for all such color pixel component values in said current set, encodes said current pixel value as a bit having a second binary state.
9. A device as in claim 1 wherein, if said encoder determines that said current one of said color pixel values exceeds said first one of said color pixel values by more than the threshold, said encoder encodes said current pixel value by creating a single byte uniquely identifying the color.
10. A device as in claim 1 wherein each of the color pixel values include color pixel component values; and
the encoder stores a first set of said color pixel component values, and receives a current set of said color pixel component values,
wherein said encoder determines whether each one of said current set of color pixel component values exceeds corresponding ones of said first set of color pixel component values by less than a threshold and, if so for all such color pixel component values in said current set, encodes said current pixel value by color match encoding.
11. A method, comprising:
receiving a stream of serial video data comprising pixel color values,
identifying a current one of said pixel color values,
identifying first and second standard pixel color values equal to two different prior pixel color values immediately adjacent a run of pixels including the current one of said pixel color values,
determining by how much the current one of said pixel color values exceeds the first standard pixel color value;
if said current one of said pixel color values exceeds the first standard pixel color value by less than a predetermined threshold, encoding said current one of said pixel color values by bit-based encoding where said bits are encoded to one of two binary states corresponding with, respectively, said first standard pixel color value;
if said current one of said pixel color values exceeds the first standard pixel color value by more than the predetermined threshold:
determining whether the current one of said pixel color values exceeds the second standard pixel color value; and
if said current one of said pixel color values exceeds the second standard pixel color value by less than a predetermined threshold, encoding said current one of said pixel color values by bit-based encoding where said bits are encoded to one of two binary states corresponding with said second standard pixel color value.
12. A method as in claim 11 wherein the color match encoding is run-length encoding.
13. A method as in claim 12 wherein said predetermined positional relationship is a location immediately to the left of a run including said current color pixel value.
14. A method as in claim 12 wherein said predetermined positional relationship is a location immediately above a start of a run including said current color pixel value.
15. A method as in claim 12 wherein said predetermined positional relationship is a common location in an immediately prior frame relative to a start of a run including said current pixel color value.
16. A method as in claim 11 wherein:
each of said pixel color values comprise plural pixel component values;
said step of determining by how much the current one of said pixel color values exceeds the first standard pixel color value includes determining by how much each pixel component value in said current one of said pixel color values exceeds corresponding ones of said first standard pixel color component values;
if all of said current pixel component values for said current one of said pixel color values exceed all of said corresponding ones of said first standard pixel color component values by less than a predetermined threshold, encoding said current pixel color component values by bit-based encoding where said bits are encoded to one of two binary states corresponding with, respectively, said first standard pixel color component values;
if any of said current pixel component values for said current one of said pixel color values exceeds any of said first standard pixel component color values by more than the predetermined threshold:
said step of determining whether the current one of said pixel color values exceeds the second standard pixel color value includes determining whether each pixel component value in said current one of said pixel color values exceeds corresponding ones of said second standard pixel color component values; and
if all of said current pixel component values exceed all of said corresponding one of said second standard pixel color component values by less than a predetermined threshold, encoding said current pixel color component values by bit-based encoding where said bits are encoded to one of two binary states corresponding with, respectively, said second standard pixel component color values.