IMPROVEMENT DEVICE AND QUANTIZATION FOR THE QUALITY OF IMAGE WITH ROI AND THE METHOD FOR OPERATING

摘要

An image improving apparatus, a quantizing device, and a quantizing method are provided to allot high bits to an ROI(Region Of Interest) and low bits to a non-ROI, thereby improving picture quality of an image. A pre-treatment unit(320) corrects images and boundaries so that a missed original image reaches an original image. An ROI-based encoder(330) performs an encoding operation on the image passed by the pre-treatment unit through a bit rate control where high bits are allotted to a specific ROI of the image and low bits are allotted to a non-ROI of the image. The ROI-based encoder includes a DCT(Discrete Cosine Transform)(334) divides the image into high-frequency component and low-frequency component by using a perpendicular relation between spatial domain and frequency domain. An ROI-based quantizing unit(335) quantizes the low-frequency component to generate a conversion coefficient, and resets the conversion coefficient of the non-ROI so that the high bits are allotted to the specific ROI and the low bits are allotted to the non-ROI. A VLC(Variable Length Coding) unit(336) removes spatial redundancy based on the conversion coefficient to finalize the encoding operation.