In this paper several methods are presented that allow improved compression of JPEG image files. This is mainly achieved through segmented entropy coding in reference to the EOBs (End-of-Block) of the 8x8 DCT transformed macroblocks. All of the algorithms discussed here are implemented in the freely available JPEG compression software 'packJPG' [9]. Our approach reduces baseline JPEG image file...

AIMS The National Screening Committee (NSC), whilst recommending the use of digital mydriatic retinal photography for diabetic retinopathy screening, has not yet accepted the use of digitally compressed images for grading. By greatly reducing the file size, however, compression of images is invaluable for storage and for its rapid transmission across computer networks. We undertook a study to c...

In this paper, a novel statistical model based on Benford’s law for the probability distributions of the first digits of the block-DCT and quantized JPEG coefficients is presented. A parametric logarithmic law, i.e., the generalized Benford’s law, is formulated. Furthermore, some potential applications of this model in image forensics are discussed in this paper, which include the detection of ...

This paper focuses on the JPEG noises, which include the quantization noise and the rounding noise, during a JPEG compression cycle. The JPEG noises in the first compression cycle have been well studied; however, so far less attention has been paid on the JPEG noises in higher compression cycles. In this work, we present a statistical analysis on JPEG noises beyond the first compression cycle. ...

The Joint Photographic Experts Group (JPEG) has recently rolled out a new still image coding standard called JPEG 2000. This standard integrates an efficient image compression scheme with functionalities required by multimedia applications, such as progressiveness up to lossless coding, region of interest coding, and error resiliency. Security is a concern in many applications, and therefore al...

We proposed a method for embedding binary data into JPEG bitstreams and extracting embedded data from JPEG bitstreams using the standard JPEG decoder. In the proposed method, we can decode the image from JPEG bitstreams into which the binary data is embedded first using the traditional standard JPEG decoder, and then we can extract the embedded binary data perfectly by the post-processing from ...

In this paper, we propose a sector-wise JPEG fragment point classification approach to classify normal and erroneous JPEG data fragments with the minimum size of 512 Bytes per fragment. The contributions of this work are two-folds: 1) a sectorwise JPEG erroneous fragment classification approach is proposed 2) a new DCT coefficient analysis method is introduced for the JPEG image content analysi...

Studies and user reports claim JPEG 2000 to be – or at least will become – the next archiving format for digital images [1]. The format offers new possibilities, such as streaming, and reduces storage consumption through lossless and lossy compression [2]. Another often claimed advantage of JPEG 2000 is that the master image can possibly serve as the access copy as well, and thus replace derive...