METHOD FOR IMPROVING LOCAL CONTRAST BASED ON DIRECTION OF IMAGE

摘要

PURPOSE: A method for improving a local contrast considering an image direction is provided to control a level for improving the local contrast according to the image size variation of a unit image block, thereby preventing the generation of noise at the unit image block in which image variation does not exist or is small. CONSTITUTION: A method for improving a local contrast includes: steps (S10,S20) of converting a unit image block in a spatial domain into a frequency domain, calculating the vertical and horizontal variation of the block in the spatial domain with the unit image block coefficient of the generated frequency domain, and calculating the image variation of the block; and steps (S30-S50) of firstly improving the vertical and the horizontal contrast of the coefficient in proportion to the image variation in order to respectively generate a vertical and a horizontal image block, giving a directional weight to the vertical and the horizontal image block, and generating a final unit image block. [Reference numerals] (AA) Start; (BB) End; (S10) Convert a frequency domain; (S20) Calculate the image variation in a space area; (S30) Generate a vertical image block; (S40) Generate a horizontal image block; (S50) Generate a final unit image block