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US 6,647,060 B1Granted
Video compression device and video compression method
AssigneeNEC Corporation
InventorHiroaki Ueda
Life of this patent
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AssigneeNEC Corporation
InventorHiroaki Ueda
Estimating the term…
A frame receiving unit calculates the number of a frame to be compressed and gets an image data from the frame. A frame checking unit checks the type of the frame and allocates required code memory. When the frame is an I frame, a frequency conversion unit converts the image to a spatial frequency, a quantization unit quantizes the spatial frequency, and a variable-length coding unit performs variable-length coding. At the same time, a reverse quantization unit performs reverse-quantization and a reverse frequency conversion unit performs reverse-conversion to create a reference image. When the frame is a P frame, a motion search unit searches for a motion of the image. The frequency conversion unit converts a difference between the image and the reference image to the spatial frequency, the quantization unit performs quantization, and the variable-length coding unit performs variable-length coding. At the same time, the reverse quantization unit performs reverse-quantization, the reverse frequency conversion unit performs reverse frequency conversion to return the reverse conversion result to the difference of the images, and a motion compensation unit combines the result with a motion-compensated reference image. When the frame is a B frame, a code indicating that the frame is the same as the reference frame is generated. The generated code is output to the allocated code memory.
A video compression method of compressing video signals, said method being processed by a frame receiving unit receiving said video signals, one frame at a time, a frame checking unit checking a type of the frame to be processed and passing control to an appropriate unit, a motion search unit searching a small block for a motion of an image, a frequency conversion unit converting the image of said small block to a spatial frequency, a quantization unit performing quantization for the image signals frequency converted by said frequency conversion unit, a reverse quantization unit performing reverse quantization for the signals output for the signals output from said reverse quantization unit, a motion compensation unit compensating a motion of the image of said small block and generating an original image, an a variable-length coding unit performing variable-length coding for the signals output from said quantization unit and outputting the signals to a compressed code output unit, said method comprising the steps of:
A computer program product stored on a storage medium for controlling a video compressing device comprising a frame receiving unit receiving said video signals, one frame at a time, a frame checking unit checking a type of the frame to be processed and passing control to an appropriate unit, a motion search unit searching a small block for a motion of an image, a frequency conversion unit converting the image of said small block to a spatial frequency, a quantization unit performing quantization for the image signals frequency-converted by said frequency conversion unit, a reverse quantization unit performing reverse quantization for the signals output from said quantization unit, a reverse frequency conversion unit performing reverse frequency conversion for the signals output from said reverse quantization unit, a motion compensation unit compensating a motion of the image of said small block and generating an original image, and a variable-length coding unit performing variable-length coding outputting the signals to a compressed code output unit, wherein the program causes the video compression device to:
Dependencies are inferred from the claim text.