Apparatus and method for compressing color index map
First Claim
1. A method for image coding, the method comprising:
- obtaining, at a video codec device, an image block for a video frame;
generating, by the video codec device, a color index map comprising a plurality of entries and representing the image block, wherein the entries are assigned color indices indicating respective colors;
attempting to predict, by the video codec device, a first color index for a first entry of the entries in accordance with a neighboring entry of the first entry in the color index map;
in response to successfully predicting the first color index for the first entry, assigning, by the video codec device in a prediction map, a first bit-value for the first entry;
in response to not successfully predicting the first color index for the first entry;
assigning, by the video codec device in the prediction map, a second bit-value for the first entry; and
adding, by the video codec device in a sequence of color indices, an actual value from the color index map for the first entry; and
transmitting, by the video codec device to a receiver, the color map index.
1 Assignment
0 Petitions
Accused Products
Abstract
Embodiments are provided for compressing a color index map in video coding applications including screen content images. An embodiment method includes obtaining, at a video codec device, an image block, and generating a color index map comprising a plurality of entries and representing the image block. Each one of the entries is assigned a color index indicating a respective color. The method further includes assigning, in a correct prediction map, a first bit-value for each one of the entries that is predictable by a neighboring entry in the color index map, and a second bit-value for each one of the entries that is unpredictable by any neighboring entry in the color index map. Further, an actual value from the color index map for the each one of the entries that is unpredictable by any neighboring entry is added in a sequence of non-predictable color indices.
18 Citations
20 Claims
-
1. A method for image coding, the method comprising:
-
obtaining, at a video codec device, an image block for a video frame; generating, by the video codec device, a color index map comprising a plurality of entries and representing the image block, wherein the entries are assigned color indices indicating respective colors; attempting to predict, by the video codec device, a first color index for a first entry of the entries in accordance with a neighboring entry of the first entry in the color index map; in response to successfully predicting the first color index for the first entry, assigning, by the video codec device in a prediction map, a first bit-value for the first entry; in response to not successfully predicting the first color index for the first entry; assigning, by the video codec device in the prediction map, a second bit-value for the first entry; and adding, by the video codec device in a sequence of color indices, an actual value from the color index map for the first entry; and transmitting, by the video codec device to a receiver, the color map index. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A method for image coding, the method comprising:
-
obtaining, at an video codec device, an image block for a video frame; selecting, by the video codec device, a plurality of major colors for the image block; assigning, by the video codec device for a pixel or a group of pixels in the image block, a color index in a color index map, wherein the color index indicates a respective color from the plurality of major colors; adding, by the video codec device, a left column and a top row to the color index map, wherein the left column and the top row comprise a plurality of entries assigned a most probable color index in the color index map; attempting to predict, by the video codec device, a first color index for a first entry of the entries in accordance with a neighboring entry in the color index map; in response to successfully predicting the first color index for the first entry, assigning, by the video codec device in a prediction map, a first bit-value for the first color index; in response to not successfully predicting the first color index for the first entry; assigning, by the video codec device, in the prediction map, a second bit-value for the first color index; and adding, by the video codec device, in a sequence of color indices, an actual value of the first color index, wherein the actual value indicates a respective color from the plurality of major colors; and transmitting, by the video codec device to a receiver, the color map index. - View Dependent Claims (13, 14, 15, 16)
-
-
17. A video codec apparatus, the video codec apparatus comprising:
-
at least one processor; and a non-transitory computer readable storage medium storing programming for execution by the at least one processor, the programming including instructions to; obtain an image block for a video frame; generate a color index map comprising a plurality of entries and representing the image block, wherein the entries are assigned color indices indicating respective colors; attempt to predict a first color index for a first entry of the entries in accordance with a neighboring entry in the color index map; in response to successfully predicting the first color index for the first entry, assign, in a prediction map, a first bit-value for the first entry; in response to not successfully predicting the first color index for the first entry; assign, in the prediction map, a second bit-value for the first entry; and add, in a sequence of color indices, an actual value from the color index map for the first entry; and transmit, to a receiver, the color map index. - View Dependent Claims (18, 19, 20)
-
Specification