Patent ID: 8345739

Claim:
A method for controlling a bit rate in image data encoding, the method comprising: setting by a reference bit amount setting unit a reference bit amount for encoding a block group having a predetermined number of blocks created by dividing image data of a frame; encoding by an encoding unit each of plural pixel values of the blocks according to a bit depth used to respectively quantize the pixel values of the blocks into a buffer; determining by an encoding completion checking unit whether encoding of the frame is completed; and comparing by a bit depth adjustment controller a group bit amount indicating an amount of encoded bits of the block group with the set reference bit amount to adjust the bit depth if encoding of a unit frame is not completed and to accordingly repeat the setting of the reference bit amount for encoding the block group having the predetermined number of blocks created by dividing image data of the frame, wherein the bit depth, used in the respective quantization for pixel values of the block group, is distinguished from the amount of encoded bits of the block group.