Lossless JPEG

About: Lossless JPEG is a research topic. Over the lifetime, 2415 publications have been published within this topic receiving 51110 citations. The topic is also known as: Lossless JPEG & .jls.

Lossless compression of pre-press images using linear color decorrelation

Abstract: Summary form only given. In the pre-press industry color images have both a high spatial and a high color resolution. Such images require a considerable amount of storage space and impose long transmission times. Data compression is desired to reduce these storage and transmission problems. Because of the high quality requirements in the pre-press industry only lossless compression is acceptable. Most existing lossless compression schemes operate on gray-scale images. In this case the color components of color images must be compressed independently. However, higher compression ratios can be achieved by exploiting inter-color redundancies. We present a new technique for exploiting inter-component redundancies. The technique is based on a modified Karhunen-Loeve transform (KLT) scheme in combination with a novel quantization scheme that guarantees losslessness. The KLT decorrelates the color components. It is recomputed on a block by block basis and is therefore spatially adaptive. Spatial redundancies are removed using predictive techniques (lossless JPEG predictor no. 7 and the CALIC-predictor). The data which remains after the (spatial and color) decorrelation should be entropy-coded, but in the current implementation of our scheme only the entropy of the remaining data is computed. Note that in each block some block-dependent information must be sent, such as entropy-coder initialization information and KLT-descriptors (i.e., the rotation angles of the orthogonal KLT-matrix).

Compression standards roles in image processing: case study

Abstract: With the rapid spread of image and video processing applications and the further development of multimedia technologies, compression standards become more and more important every day. This study was conducted to investigate the role of compression standards in image processing. Digital watermarking algorithm for securing multimedia application is considered one of the most important applications heavily rely on compression standards. It was selected to perform our experimental study by employing wavelet and JPEG compression standards. An analysis of the experiment results indicated that the wavelet outperform JPEG compression standard and applications implemented wavelet have better performance than those implemented JPEG.

An efficient method for lossless compression of bi-level ROI maps of hyperspectral images

Abstract: While one can achieve very large size reduction on a hyperspectral image dataset by preserving only some regions-of-interest (ROI's), the bi-level map that describes the locations of the ROI pixels tend to defy efficient compression due to the somewhat “random” nature of ROI pixel locations. To this end, we proposed a novel method for lossless compression of these ROI maps. In this method, we first partitioned a bi-level map into equally sized blocks. We then converted the bi-level pixels within each block into a block symbol. Based on the observation that the most probable blocks tend to contain either all zeros or all ones, we chose to run-length code these most probable block symbols before applying Huffman code in order to achieve high compression, whereas we applied a separate Huffman code on other less probable block symbols. Thus this biased run-length coding method differs from conventional approaches where all symbols are run-length coded. Tests on NASA's AVIRIS dataset showed that the proposed method could provide significant improvements over various bi-level image compression techniques (including JBIG2 and lossless JPEG 2000) on the ROI maps.

Toward privacy-preserving JPEG image retrieval

Abstract: This paper proposes a privacy-preserving retrieval scheme for JPEG images based on local variance. Three parties are involved in the scheme: the content owner, the server, and the authorized user. The content owner encrypts JPEG images for privacy protection by jointly using permutation cipher and stream cipher, and then, the encrypted versions are uploaded to the server. With an encrypted query image provided by an authorized user, the server may extract blockwise local variances in different directions without knowing the plaintext content. After that, it can calculate the similarity between the encrypted query image and each encrypted database image by a local variance-based feature comparison mechanism. The authorized user with the encryption key can decrypt the returned encrypted images with plaintext content similar to the query image. The experimental results show that the proposed scheme not only provides effective privacy-preserving retrieval service but also ensures both format compliance and file size preservation for encrypted JPEG images.