JPEG compression is a commonly used method of lossy for digital images. The degree can be adjusted by the choice quality factor QF. Each software associates this value to quantization table, which an 8 x matrix quantize DCT coefficients image. We propose recovering table relying only on image information, without any metadata from file header; thus proposed applied uncompressed format detect pr...

JPEG 2000, the new ISO/ITU-T standard for still image coding, is about to be finished. Other new standards have been recently introduced, namely JPEG-LS and MPEG-4 VTC(H.264). This paper compares the set of features offered by JPEG 2000, and how well they are fulfilled, versus JPEG and MPEG-4 VTC(H.264). The study concentrates on compression efficiency and functionality set, while addressing ot...

Palette images are widely used on the World Wide Web (WWW) and in game-cartridge applications. Many images used on the WWW are stored and transmitted after they are compressed losslessly with the standard graphics interchange format (GIF), or portable network graphics (PNG). Well-known 2-D compression schemes, such as JPEG-LS and JPEG-2000, fail to yield better compression than GIF or PNG due t...

∗ Corresponding author. Fax: +30 61 997456 Email addresses: [email protected] (A.N. Skodras), [email protected] (C.A. Christopoulos), [email protected] (T. Ebrahimi). Abstract: With the increasing use of multimedia technologies, image compression requires higher performance as well as new features. To address this need in the specific area of still image encoding, a ne...

In this article, we study a recently proposed method for improving empirical security of steganography in JPEG images which the sender starts with an additive embedding scheme symmetrical costs ± 1 changes and then decreases cost one these based on image obtained by applying deblocking (JPEG dequantization) algorithm to cover JPEG. This approach provides rather significant gains at negligi...