Differential coding of intra directions (DCIC)

An apparatus for encoding an image programmed in a controller in a device comprising:

• a. an image gradient vector module for applying operators to neighboring pixels for obtaining an image gradient vector for each of the pixels;
• b. an edge detection module for determining an edge direction for each of the pixels by taking a perpendicular direction to each of the gradient vectors;
• and
• c. a best direction module for predicting a best direction using the edge direction of each of the pixels, wherein the best direction is adjusted by a direction adjustment, wherein the direction adjustment is implemented using discrete values with a quantization step size, wherein the quantization step size implements a confidence measure, wherein the higher the confidence measure, the smaller the quantization step size.

A device comprising:

• a. a memory for storing an application, the application for:
• i. applying operators to neighboring pixels of a block to obtain an image gradient vector for each of the pixels;
• ii. determining an edge direction for each of the pixels by taking a perpendicular direction to each of the gradient vectors;
• and
• iii. predicting a best direction using the edge direction for each of the pixels, wherein the best direction is adjusted by a direction adjustment, wherein the direction adjustment is implemented using discrete values with a quantization step size, wherein the quantization step size implements a confidence measure, wherein the higher the confidence measure, the smaller the quantization step size;
• and
• b. a processing component coupled to the memory, the processing component configured for processing the application.

A method of encoding an image programmed in a controller in a device comprising:

• a. differentially encoding is implemented for a direction if the direction is close to suggested directions of neighbors of the direction;
• and
• b. otherwise, using a simple fixed length code to signal the direction of the direction, wherein differentially encoding further comprises:
• i. applying operators to neighboring pixels of a block to obtain an image gradient vector for each of the pixels;
• ii. determining an edge direction for each of the pixels by taking a perpendicular direction to each of the gradient vectors;
• and
• iii. predicting a best direction using the edge direction for each of the pixels, wherein the best direction is adjusted by a direction adjustment, wherein the direction adjustment is implemented using discrete values with a quantization step size, wherein the quantization step size implements a confidence measure, wherein the higher the confidence measure, the smaller the quantization step size.