We propose a computationally-efficient variant of the shapeadaptive discrete cosine transform (SA-DCT) currently considered for MPEG-4. Although the SA-DCT complexity is acceptable for 8 8 blocks, it is very high when complete regions are processed at once. To reduce the SA-DCT complexity, we replace its 1-D DCT with a quasi-DCT algorithm and we assure that the quasi-DCT basis functions are ver...

This paper presents an M-channel (M = 2n (n ∈ N)) integer discrete cosine transforms (IntDCTs) based on fast Hartley transform (FHT) for lossy-to-lossless image coding which has image quality scalability from lossy data to lossless data. Many IntDCTs with lifting structures have already been presented to achieve lossy-to-lossless image coding. Recently, an IntDCT based on direct-lifting of DCT/...

Alternative fully DCT-based video codec architectures have been proposed in the past to address the shortcomings of the conventional hybrid motion compensated DCT video codec structures traditionally chosen as the basis of implementation of standardcompliant codecs. However, no prior effort has been made to ensure interoperability of these two drastically different architectures so that fully D...

In this paper, we propose a video hash scheme that utilizes image hash and spatio-temporal information contained in video to generate video hash. A video clip is firstly segmented to shots, and video hash is derived in unit of shot. We notice that for video hash applications in identification and verification, reference video and suspected video always appear in pair. Therefore, we propose to d...

The shape-adaptive DCT (SA-DCT) [12, 13] is a low-complexity transform which can be computed on a support of arbitrary shape. Particularly suited for coding image patches in the vicinity of edges, the SA-DCT has been included in the MPEG-4 standard [7]. The use of this shape-adaptive transform for grayscale image denoising has been recently proposed [3, 2], showing a remarkable performance. In ...

Discrete trigonometric transforms, such as the discrete cosine transform (DCT) and the discrete sine transform (DST), have been extensively used in signal processing for transform-based coding. The even type-II DCT, used in image and video coding, became specially popular to decorrelate the pixel data and minimize the spatial redundancy. Albeit this DCT tends to be the most often used, it integ...

This paper presents a comparative study of watermarking schemes. The embedding of watermark is performed after the image normalization. By normalization process the normalized image achieves invariance properties against geometric attacks which include rotation, scaling and translation of an image. Watermarking is done using five methods DCT Zigzag, DCT blocks, DWT, Zernike transform, SVD-DCT. ...

This paper describes a new technique to implement operations on compressed digital video images that allows many image manipulation operations to be performed 50 to 100 times faster than the corresponding algorithms operating on uncompressed images. This is accomplished by performing the operations directly on the compressed data in the DCT domain. In this paper, we show how to transform image ...

In the companion paper, we addressed the low-power DCT/IDCT VLSI architectures of linear complexity increase based on the multirate approach. In this paper, we will discuss other aspects of the low-power design. Firstly, we consider the design of low-power architectures that can lower the power consumption at only O(log M) increase in hardware complexity. Next, we will extend the low-power DCT ...

In this paper a hybrid fractal and Discrete Cosine transform (DCT) coder is developed. Drawing on the ability of DCT to remove inter-pixel redundancies and on the ability of fractal transforms to capitalize on long-range correlations within the image, the hybrid coder performs an operationally optimal, in the rate-distortion sense, bit allocation among coding parameters. An orthogonal basis fra...