Separate plane compression using plurality of compression methods including ZLN and ZLD methods
Methods, medium, and machines which compress, enhance, encode, transmit, decode, decompress and display digital video images. Real time compression is achieved by sub-sampling each frame of a video signal, filtering the pixel values, and encoding. Real time transmission is achieved due to high levels of effective compression. Real time decompression is achieved by decoding and decompressing the encoded data to display high quality images. A receiver can alter various setting including, but not limited to, the format for the compression, image size, frame rate, brightness and contrast. In a Doppler improvement aspect of the invention, Doppler velocity scales are incorporated into grayscale compression methods using two bits. Variable formats may be selected and Doppler encoding can be turned on and off based on the image content. A separate plane compression aspect of the invention provides for distinguishing between regions of an image, separating and masking the original image into multiple image planes, and compressing each separated image plane with a compression method that is optimal for its characteristics. From a video stream, separate image streams can be compressed with different methods, and the separate image streams can be stored or transmitted at different rates. Alternatively, frame differencing can be applied to the separated streams. Regions may be distinguished by user input or by automated analysis of the characteristics of various regions of an image, such as the presence of Doppler enhanced pixels.
1. A system for compressing of a plurality of video frames which make up a video stream, comprising:
a) a video digitizer configured to digitize a frame from said video frames;
b) a video memory which is able to receive a plurality of pixels from said video digitizer;
c) at least one encoding means for generating encoded data,
d) a memory which is able to store said encoded data;
e) an input/output device,
wherein said at least one encoding means comprises a compression means for counting repeated instances of a pixel value comprising a number of pixel bits sub-sampled from each pixel when scanning said plurality of pixels and outputting a series of encoded data comprising a combined run-length field and a data field,
i) wherein the data field of each encoded data element comprises a number in the range from zero to the maximum value of said number of sub-sampled pixel bits, and
ii) wherein the run-length field of each encoded data element comprises the repeat count of the value in said data field.
2. The system of claim 1 wherein said encoding means variably selects one of a set of 3, 4, 5, 8, 9, 12, 15, 16, and 24, as the number of pixel bits sub-sampled from each pixel,
wherein the number of pixel bits sub-sampled is less than the number of bits of the pixel being sub-sampled.
3. The system of claim 2 wherein said pixel value is extracted from the most significant bits of each color component.
4. The system of claim 1 wherein said input/output device is a storage medium.
5. The system of claim 1 wherein said input/output device is a communications transmission channel.
6. The system of claim 1 further comprising:
a) a second encoding means, and
b) a means for separating each frame into a plurality of planes, wherein at least one plane contains a first set of pixels having a distinguishing characteristic forming a region and mask pixels having a uniform pixel value, and at least another plane contains a second set of pixels from another region, and
wherein the first compression means is used to compress one of said planes,
wherein a second encoding means comprises a second compression means for compressing another of said planes.
7. The system of claim 6 wherein one or more of said plurality of video frames is a Doppler enhanced frame which contains both grayscale pixel values and Doppler enhanced pixels values,
the system further comprising a memory device containing a plurality of lookup tables,
wherein the means for separating each frame into a plurality of planes separates grayscale pixel values into a grayscale plane and Doppler enhanced pixels values into a Doppler enhanced plane,
wherein the first compression means is used to compress the grayscale plane,
wherein the second compression means is used to compress the Doppler enhanced plane by:
i) determining a scale for each of said pixels,
ii) selecting a code from the plurality of lookup tables based on said scale and on a number of pixel bits sub-sampled from each pixel,
iii) counting repeated instances of said code,
iv) encoding said scale and said code,
v) and outputting a series of encoded data comprising a combined second run-length field and a second data field,
(1) wherein the second data field of each encoded data element comprises the scale and the code, and
(2) wherein the second run-length data field of each encoded data element comprises the repeat count of the second data field.
8. The system of claim 6 wherein said distinguishing characteristic is the effective color depth of each pixel of a current frame.
9. The system of claim 6 wherein said distinguishing characteristic is based on user selection of a region.
10. The system of claim 9 wherein said user selection is based on user input through an input device.
11. The system of claim 10 wherein said user input is detection of user eye movement.
12. The system of claim 6 wherein said distinguishing characteristic is the region of most change between adjacent frames in said video stream.
13. The system of claim 6 wherein said distinguishing characteristic is based on detection of a marker.
14. A system for compressing a video stream, said system comprising:
a) an image source providing said video stream, said video stream comprising a plurality of video frames,
b) a means for separating each frame into a plurality of planes, wherein at least one plane contains a first set of pixels having a distinguishing characteristic forming a region and mask pixels having a uniform pixel value, and at least another plane contains a second set of pixels from another region, and
c) a means for compressing each of said plurality of planes into one of a plurality of encoded images, wherein said compressing means comprises a plurality of distinct compression methods,
wherein said at least one plane containing the first set of pixels is compressed using one compression method, and wherein said at least another plane containing the second set of pixels is compressed using another compression method,
wherein at least one of said regions is nonrectangular,
wherein at least one plane contains all of the pixels from said at least one nonrectangular region,
and wherein at least one other plane contains none of the pixels from said at least one nonrectangular region, and
wherein one of the plurality of distinct compression methods comprises a first compression method comprising the steps of:
i) obtaining a plurality of digital pixels representing each frame of the plurality of video frames, each of said pixels having an original number of bits;
ii) counting repeated instances of a pixel value comprising a number of pixel bits sub-sampled from each pixel when scanning said plurality of digital pixels;
iii) forming a series of encoded data comprising a combined data field and a run-length field,
(1) wherein the data field of each encoded data element comprises a number in the range from zero to the maximum value of said number of sub-sampled pixel bits, wherein the maximum value is two to the power of N minus one, namely 2 N −1, where N is said number of sub-sampled pixel bits, and
(2) wherein the run-length field of each encoded data element comprises the repeat count of the value in said data field; and
iv) storing said encoded data in a temporary memory,
wherein another of the plurality of distinct compression methods comprises a second compression method which is used to compress at least some of the frames,
whereby the overall compressed size for said video stream, namely the combined size of the encoded images, is less than the compressed size when each frame of the video stream is compressed with a single high quality compression method.
15. The system of claim 14 wherein said pixel value, comprising a number of pixel bits sub-sampled from each pixel when scanning said plurality of digital pixels, is extracted from the most significant bits of each color component.
16. A method of reducing the size of a video stream, said method comprising the steps of:
a) providing said video stream, said video stream comprising a plurality of video frames,
b) separating each frame into a plurality of planes, wherein at least one plane contains a first set of pixels having a distinguishing characteristic forming a region and mask pixels having a uniform pixel value, and at least another plane contains a second set of pixels from another region, and
c) compressing each of said plurality of planes into one of a plurality of encoded images, using a plurality of distinct methods, wherein said at least one plane containing the first set of pixels is compressed using one compression method, and wherein said at least another plane containing the second set of pixels is compressed using another compression method,
wherein at least one of said regions is nonrectangular,
wherein at least one plane contains all of the pixels from said at least one nonrectangular region,
and wherein at least one other plane contains none of the pixels from said at least one nonrectangular region, and
wherein one of the plurality of distinct compression methods comprises a first compression method comprising the sub-steps of:
i) scanning a plurality of digital pixels representing each frame of the plurality of video frames, each of said pixels having an original number of bits;
ii) counting repeated instances of a pixel value comprising a number of pixel bits sub-sampled from each pixel when scanning said plurality of digital pixels;
iii) forming a series of encoded data comprising a combined data field and a run-length field,
(1) wherein the data field of each encoded data element comprises a number in the range from zero to the maximum value of said number of sub-sampled pixel bits, wherein the maximum value is two to the power of N minus one, namely 2 N −1, where N is said number of sub-sampled pixel bits, and
(2) wherein the run-length field of each encoded data element comprises the repeat count of the value in said data field; and
iv) storing said encoded data in a temporary memory.
17. The method of claim 16 wherein said pixel value, comprising a number of pixel bits sub-sampled from each pixel when scanning said plurality of digital pixels, is extracted from the most significant bits of each color component.
18. A method, comprising:
separating a frame of a video stream into a plurality of planes, wherein at least one plane contains a first set of pixels having a distinguishing characteristic forming a region and mask pixels having a uniform pixel value, and at least another plane contains a second set of pixels from another region, and
compressing each of said plurality of planes into one of a plurality of encoded images, using a plurality of distinct methods, wherein said at least one plane containing the first set of pixels is compressed using one compression method, and wherein said at least another plane containing the second set of pixels is compressed using another compression method;
wherein one of the plurality of distinct compression methods comprises a first compression method that includes:
scanning a plurality of digital pixels of the frame, each of said pixels having an original number of bits;
counting repeated instances of a pixel value comprising a number of pixel bits sub-sampled from each pixel when scanning said plurality of digital pixels; and
forming a series of encoded data comprising a combined data field and a run-length field;
wherein the data field of each encoded data element comprises a number in the range from zero to the maximum value of said number of sub-sampled pixel bits, wherein the maximum value is two to the power of N minus one, namely 2 N −1, where N is said number of sub-sampled pixel bits, and wherein the run-length field of each encoded data element comprises the repeat count of the value in said data field.
19. The method of claim 18 , wherein at least one of said regions is nonrectangular, wherein at least one plane contains all of the pixels from said at least one nonrectangular region, and wherein at least one other plane contains none of the pixels from said at least one nonrectangular region.
20. An apparatus, comprising:
means for separating a frame of a video stream into a plurality of planes, wherein at least one plane contains a first set of pixels having a distinguishing characteristic forming a region and mask pixels having a uniform pixel value, and at least another plane contains a second set of pixels from another region, and
means for compressing each of said plurality of planes into one of a plurality of encoded images, using a plurality of distinct methods, including first compression means for compressing said at least one plane containing the first set of pixels, and second compression means, distinct and separate from said first compression means, for compressing said at least another plane containing the second set of pixels;
wherein at least one of said first and second compression means comprises:
means for scanning a plurality of digital pixels of the frame, each of said pixels having an original number of bits;
means for counting repeated instances of a pixel value comprising a number of pixel bits sub-sampled from each pixel when scanning said plurality of digital pixels; and
means for forming a series of encoded data comprising a combined data field and a run-length field;
wherein the data field of each encoded data element comprises a number in the range from zero to the maximum value of said number of sub-sampled pixel bits, wherein the maximum value is two to the power of N minus one, namely 2 N −1, where N is said number of sub-sampled pixel bits, and wherein the run-length field of each encoded data element comprises the repeat count of the value in said data field.
21. At least one non-transitory computer-readable storage medium comprising a plurality of executable instructions configured to enable an apparatus, in response to execution of the instructions by the apparatus, to:
separate a frame of a video stream into a plurality of planes, wherein at least one plane contains a first set of pixels having a distinguishing characteristic forming a region and mask pixels having a uniform pixel value, and at least another plane contains a second set of pixels from another region, and
compress each of said plurality of planes into one of a plurality of encoded images, using a plurality of distinct methods, wherein said at least one plane containing the first set of pixels is compressed using a first compression method, and said at least another plane containing the second set of pixels is compressed using a second compression method, distinct and separate from the first compression method;
wherein either the first compression method or the second compression method includes:
scanning a plurality of digital pixels of the frame, each of said pixels having an original number of bits;
counting repeated instances of a pixel value comprising a number of pixel bits sub-sampled from each pixel when scanning said plurality of digital pixels; and
forming a series of encoded data comprising a combined data field and a run-length field;
wherein the data field of each encoded data element comprises a number in the range from zero to the maximum value of said number of sub-sampled pixel bits, wherein the maximum value is two to the power of N minus one, namely 2 N −1, where N is said number of sub-sampled pixel bits, and wherein the run-length field of each encoded data element comprises the repeat count of the value in said data field.