Abstract: An apparatus for variable bit rate control in moving picture compression. First, a total activity measure for the current picture to be encoded in a set of consecutive pictures is calculated. Based on the total activity measure of the current picture and an activity-to-complexity ratio of a previously encoded picture of the same type in the set of consecutive pictures, a complexity measure of the current picture is estimated. A statistical complexity measure is then calculated from the complexity measure of the current picture. A target bit budget is allocated to the current picture depending on the instantaneous rate, the complexity measure and the instantaneous complexity measure. After encoding the current picture, the activity-to-complexity ratio for the current picture is computed based on the total activity measure, actual bits consumed by the current picture and an average of actual quantization step sizes used to encode the current picture.

Abstract: A total activity measure for a current picture to be encoded in a set of consecutive pictures of a video sequence is calculated first. Based on the total activity measure of the current picture and an activity-to-complexity ratio of a previously encoded picture of the same type in the set of consecutive pictures, a complexity measure of the current picture is estimated. With the estimated complexity measure of the current picture, an instantaneous complexity measure for the set of consecutive pictures is updated. A target bit budget is allocated to the current picture depending on the estimated complexity measure and the instantaneous complexity measure. The current picture is encoded according to the target bit budget, and the activity-to-complexity ratio for the current picture is computed based on the total activity, actual bits consumed by the current picture, and the average quantization step size of the current picture.

Abstract: A fast line drawing method. First, the coordinates of two end points are received and a current point is assigned to one of the end points. The differences of x and y coordinates (?x and ?y) and the sum of error E are computed, the integer part of ?x over ?y is denoted as Q. The current point is checked to determine whether it has reached the end point. If not and the value of E is negative, a point at the current point is drawn. The y-coordinate of the current point and E are updated by (Y+1) and (E?2?x) respectively if E is non-negative, a span of pixels from (X,Y) to (X+Q?1,Y) are drawn if the coordinate of last of Q points is less than the end point. Otherwise, a span of pixels from (X,Y) to (x2,Y) are drawn.

Abstract: An apparatus for variable bit rate control in moving picture compression. First, a total activity measure for the current picture to be encoded in a set of consecutive pictures is calculated. Based on the total activity measure of the current picture and an activity-to-complexity ratio of a previously encoded picture of the same type in the set of consecutive pictures, a complexity measure of the current picture is estimated. A statistical complexity measure is then calculated from the complexity measure of the current picture. A target bit budget is allocated to the current picture depending on the instantaneous rate, the complexity measure and the instantaneous complexity measure. After encoding the current picture, the activity-to-complexity ratio for the current picture is computed based on the total activity measure, actual bits consumed by the current picture and an average of actual quantization step sizes used to encode the current picture.

Abstract: A method and apparatus for rate control in moving picture video compression. According to the present invention, a total activity measure for a current picture to be encoded in a set of consecutive pictures of a video sequence is calculated first. Based on the total activity measure of the current picture and an activity-to-complexity ratio of a previously encoded picture of the same type in the set of consecutive pictures, a complexity measure of the current picture is estimated. A target bit budget is allocated to the current picture depending on the estimated complexity measure of the current picture. Then, the current picture is encoded according to the target bit budget. After encoding the current picture, the activity-to-complexity ratio for the current picture is computed based on the total activity, actual bits consumed by the current picture, and the average quantization step size of the current picture.

Abstract: A fast line drawing method. First, the coordinates of two end points are received and a current point is assigned to one of the end points. The differences of x and y coordinates (&Dgr;x and &Dgr;y) and the sum of error E are computed, the integer part of &Dgr;x over &Dgr;y is denoted as Q. The current point is checked to determine whether it has reached the end point. If not and the value of E is negative, a point at the current point is drawn. The y-coordinate of the current point and E are updated by (Y+1) and (E−2&Dgr;x) respectively if E is non-negative, a span of pixels from (X,Y) to (X+Q-1,Y) are drawn if the coordinate of last of Q points is less than the end point. Otherwise, a span of pixels from (X,Y) to (x2,Y) are drawn.

Abstract: A method for contrast enhancement of pixel data of a decompressed color image includes the steps of computing I component values in an HSI color space for the pixel data of the color image, computing an image I component value which is an average of the computed I component values, and enhancing each of the pixel data of the color image according to the image I component value. An apparatus for contrast enhancement of pixel data of a decompressed color image is also disclosed.

Abstract: A method and system for compressing graphic data by dividing the data into segments is disclosed. The size of the divided segment is programmable. A frame buffer partitioned into a compressed frame buffer and an uncompressed frame buffer stores graphic data. Each segment of the graphic data is compressed by three different algorithms that encode the graphic data as a plurality of code-words. Each code-word for the segment is taken from the algorithm that can compress the largest number of pixels in the code-word. A header is used to indicate the number of code-words and the compression method used in each code-word. The total number of bytes obtained from the compression of a segment is compared to a pre-defined limit to determine if the compression of the segment is successful. The successfully compressed data of a segment are written to the compressed frame buffer. A compression status flag buffer is used to identify if a segment is compressed or not.