Compressed image reproduction based on block decomposition
نویسنده
چکیده
A compressed image reproduction scheme is proposed by properly decomposing and manipulating the coefficients of discrete cosine transform (DCT) directly in the compressed domain. The basic idea of the proposed approach is to decompose each DCT block into several sub-blocks and to adjust the brightness and detail components of a given image for compressing dynamic range and enhancing contrast. Image reproduction based on the subblock decomposition can be done more precisely than any approach based on the normal block-sized approach. First, DCT coefficients of each block are decomposed into several sub-blocks. Next each sub-block’s coefficients are separated into brightness and detail components, and treated differently according to content analysis. Then, the enhanced coefficients are projected on the constraint sets to avoid some artefacts, and are composed back to the original order. The main advantages of the proposed algorithm are that (i) it can enhance the dynamic range and details without affecting the compressibility of the given image since it operates directly in the compressed domain, and (ii) it does not boost blocking artefacts around big edges without any further processing. In order to evaluate the proposed scheme, several base-line approaches are described and compared using enhancement quality measures.
منابع مشابه
Singular Value Decomposition based Steganography Technique for JPEG2000 Compressed Images
In this paper, a steganography technique for JPEG2000 compressed images using singular value decomposition in wavelet transform domain is proposed. In this technique, DWT is applied on the cover image to get wavelet coefficients and SVD is applied on these wavelet coefficients to get the singular values. Then secret data is embedded into these singular values using scaling factor. Different com...
متن کاملImage Compression based on SVD and MPQ-BTC
In this paper we will provide a new way of images compression based on two mathematic concepts, these two concepts are Singular Value Decomposition (SVD), and Block Truncation Coding. The input image either is in JPEG format or in BMP format, and the current way suitable for both color and gray scale images. The input image will be compressed first by reducing the image matrix rank, which achie...
متن کاملSemantic-Based Image Retrial in the VQ Compressed Domain using Image Annotation Statistical Models
متن کامل
Stereo video coding based on quad-tree decomposition of B–P frames by motion and disparity interpolation
A new optimised technique for coding stereoscopic image sequences is presented and compared with already known methods. The proposed technique, called enhanced interpolated motion and disparity estimation (EIMDE), is based on the joint method, which encodes the frames of the right image sequence by exploiting both the temporal redundancy of the same sequence and the disparity redundancy with th...
متن کاملBlock image retrieval based on a compressed linear quadtree
Based on a compressed linear quad tree, a data structure is proposed which is more than a structure to compress a gray-level or color image, but a structure, which can be applied to retrieve a block image. This compressed linear quadtree may directly extract a detailed block image without decompressing the compressed data of the original image.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2009