Hsin-Hui Chen

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In the conventional JPEG algorithm, an image is divided into eight by eight blocks and then the 2-D DCT is applied to encode each block. In this paper, we find that, in addition to rectangular blocks, the 2-D DCT is also orthogonal in the trapezoid and triangular blocks. Therefore, instead of eight by eight blocks, we can generalize the JPEG algorithm and(More)
In this paper, a color image retrieval scheme based on quadtree classified vector quantization (QCVQ) is proposed. This scheme not only captures intra-block correlation but also exploits the visual importance of image blocks to efficiently describe the content of images in a compressed domain. In the proposed algorithm, a query image is first divided by(More)
The Golomb code is a special case of the Huffman code that is optimal for the data with a geometric distribution. In this paper, we generalize the Golomb code by using the joint probability. In image coding, there are many conditions that the probability of a data not only has a geometric distribution but also depends on another data. Based on this idea, we(More)
With the fast development of multimedia, it is crucial to find the way to search image database effectively. The vector quantization (VQ) based image retrieval method is popular in recent years. In this paper, we propose the quadtree classified vector quantization (QCVQ) scheme to improve the VQ method by exploiting the visual importance of image blocks and(More)
Image interpolation is important for computer vision. Most of the existing image interpolation methods are based on the optimization in the mean square error (MSE) sense. In this paper, we incorporate the structural similarity (SSIM) based metric into the framework of the nonlocal edge-directed image interpolation (NLEDI) method. In the proposed algorithm,(More)
Coefficient scanning plays an important role in block-based image and video coding standards, such as JPEG, MPEG, and the latest H.264/AVC. In these coding standards, the zigzag scanning method is used for image / frame coding and the field scanning method is used for field coding. Although these scanning methods can achieve acceptable coding efficiency,(More)
In this paper, a new adaptive scanning scheme, which is called local prediction based adaptive scanning (LPBAS), is proposed for discrete cosine transform (DCT) based image compression techniques including JPEG and H.264/AVC intra coding. The conventional zigzag scan order is widely used in image and video coding standards, but it ignores the statistical(More)