JPEG is one of the most widely used image compression method, but it causes annoying blocking artifacts at low bit-rates. Sparse representation is an efficient technique which can solve many inverse problems in image processing applications such as denoising and deblocking. In this paper, a post-processing method is proposed for reducing JPEG blocking effects via sparse representation. In this ...

The JPEG image compression method has been widely implemented in digital camera devices. The quantization process plays a primary role in JPEG image compression. The quantization process is used to determine the visibility threshold of the human visual system. The quantization tables are generated from a series psychovisual experiments from several angle points of experimental views. This paper...

In this paper we present an algorithm to further compress JPEG images without loss. The main contribution of this work is a sorting transform that allows reducing inter-block redundancy not exploited by the standard JPEG still image compression algorithm. Inter subband redundancy is also reduced by grouping of coefficients with similar statistics and entropy encoding in adaptive contexts. Teste...

This paper presents two JPEG steganographic methods using quantization index modulation (QIM) in the discrete cosine transform (DCT) domain. The two methods approximately preserve the histogram of quantized DCT coefficients, aiming at secure JPEG steganography against histogram-based attacks. In comparison with F5 as a representative JPEG steganography, the proposed methods show high performanc...

In this paper, we propose a hardware architecture of realtime JPEG encoder for 1.4 mega pixels CMOS image sensor SoC which can be applied to mobile communication devices. The proposed architecture has an efficient interface scheme with CMOS image sensor and other peripherals for real-time encoding. The JPEG encoder supports the baseline JPEG mode, and processes motion images of which resolution...