Frame memory compression is a widely used image compression technique that aims to reduce the size of the frame memory in display panels such as those containing LCD and OLED technologies. Recent LCD panels use the RG...
详细信息
Frame memory compression is a widely used image compression technique that aims to reduce the size of the frame memory in display panels such as those containing LCD and OLED technologies. Recent LCD panels use the RGBW color domain to replace the traditional RGB domain in order to enhance the brightness of LCD panels with the addition of a white component. The additional component increases the size of the frame memory but necessitates an aggressive compression algorithm. This paper proposes a novel compression algorithm for RGBW components that improves the efficiency of block truncation coding (BTC), which is widely used for LCD overdrive. The proposed low-complexity adaptive multi-level block truncation coding (LAM-BTC) algorithm codes RGBW color data with a width of ten bits. It adaptively selects two-level BTC or four-level BTC to enhance the quality of the images, for which a low-complex level selection scheme is used. Four-level BTC in the proposed algorithm codes two representative values (RV) in four RVs and infers the other two RVs using inter-color correlation. In spite of the reduced complexity, the average peak signal-to-noise ratio (PSNR) of the proposed algorithm is 0.54 dB higher than that of the previous AM-BTC at a compression ratio of eight(1).
Various variants and hybrid approaches evolved from the origin of Delp and Mitchell's block truncation coding (BTC) or moment preserving quantizer (MPQ) have formed a niche as an effective and simple image compres...
详细信息
Various variants and hybrid approaches evolved from the origin of Delp and Mitchell's block truncation coding (BTC) or moment preserving quantizer (MPQ) have formed a niche as an effective and simple image compression methodology with attractive coding performance achieved at moderate bitrates. As ETC is still lacking a fundamental error analysis, in this paper we present some fundamental insights regarding one-bit (or two-level) BTC's truncation error by providing mathematical analysis as well as novel geometric interpretation. We further show that the mean-square error (MSE) of Lema and Mitchell's absolute moment block truncation coding (AMBTC) is always bounded below (i.e., less than or equal to) that of ETC. Therefore, with additional advantages in computation and implementation, AMBTC is always superior. Furthermore, we developed a new adaptive equal sign position optimization (ESPO) algorithm for optimum pixel classification. Our quantization error analysis shows that incorporating the ESPO algorithm into conventional AMBTC or ETC achieves minimum MSE in either case. (C) 2000 Elsevier Science B.V. All rights reserved.
In this paper, we propose a novel perceptual image hashing scheme based on block truncation coding (BTC). In the proposed scheme, the pre-processing is first applied on original image through bilinear interpolation, G...
详细信息
In this paper, we propose a novel perceptual image hashing scheme based on block truncation coding (BTC). In the proposed scheme, the pre-processing is first applied on original image through bilinear interpolation, Gaussian low-pass filtering, and singular value decomposition (SVD) to construct a secondary image for regularization. Then, BTC is conducted on the secondary image to extract perceptual image features, and the low and high reconstruction levels and the feature matrix of corresponding binary map after the computation of center-symmetrical local binary pattern (CSLBP) are compressed with quantization and data dimensionality reduction of PCA to produce the final compact binary hash. Experimental results demonstrate that the proposed scheme has the satisfactory performances of robustness, anti-collision, and security. (C) 2016 Elsevier Inc. All rights reserved.
Three novel image compression schemes are proposed here for multimedia applications. The schemes are designed to combine the advantages of vector quantization and block truncation coding based on quadtree segmentation...
详细信息
Three novel image compression schemes are proposed here for multimedia applications. The schemes are designed to combine the advantages of vector quantization and block truncation coding based on quadtree segmentation. A new Vector quantization scheme, calf ed subsampling VQ (SVQ), is proposed and used in the new schemes. The spatial correlation between neighboring image blocks and uniformity in variable-sized image blocks is exploited in these schemes. Simulation results show that the new schemes have succeeded in achieving better coding performance with subjective image quality at low bit rates. (C) 2000 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(00)021 02-4].
A novel image compression scheme based on absolute moment block truncation coding (AMBTC) is proposed. The quadtree segmentation technique is employed in this scheme to exploit the variable-block-sized segmentation. I...
详细信息
A novel image compression scheme based on absolute moment block truncation coding (AMBTC) is proposed. The quadtree segmentation technique is employed in this scheme to exploit the variable-block-sized segmentation. In addition, the concept of using visual patterns to reduce the storage cost of the BTC bit plane is incorporated into this scheme. Finally, the bit plane omission technique is employed if these two quantization levels in each image block are quite similar. According to the experimental results, it is shown that the proposed scheme requires very little computational complexity. Besides, a good image quality of the compressed image can be obtained while the required bit rate is relatively low. In other words, the proposed scheme indeed provides a good approach to compress digital images with little computational cost at a low bit rate. (C) 2003 Society of Photo-Optical Instrumentation Engineers.
block truncation coding (BTC) is an efficient compression technique for its inherent simple coding strategy. However, the annoying blocking effect and false contour accompanied in high coding gain configurations make ...
详细信息
block truncation coding (BTC) is an efficient compression technique for its inherent simple coding strategy. However, the annoying blocking effect and false contour accompanied in high coding gain configurations make the applications relatively limited compares to some up-to-date compression schemes. For this, Error-Diffused block truncation coding (EDBTC) is proposed to solve these problems and obtain satisfactory results. Unfortunately, the EDBTC sacrifices the parallel advantage of traditional BTC. Moreover, the number of diffused directions of EDBTC can be reduced to obtain higher efficiency. For these, the Interlaced Error-Diffused block truncation coding (IEDBTC) is proposed in this work to claim back the parallel advantage. In addition, the diffused elements are also reduced from four to two with the proposed optimization procedure while preserving the image quality.
This paper presents a modified block truncation coding scheme for the compression of images. We first design a set of binary edge patterns, which are visually significant, to approximate the bit plane of an image bloc...
详细信息
This paper presents a modified block truncation coding scheme for the compression of images. We first design a set of binary edge patterns, which are visually significant, to approximate the bit plane of an image block. An interblockcoding scheme, utilizing the spatial correlation between neighboring blocks, is then developed for coding of the sample mean and standard deviation of a block. Simulation results indicate that the bit rate is significantly reduced without introducing noticeable degradation in the reconstructed images.
In this paper, a novel detection and recovery system is proposed for image authentication based on two compression schemes: block truncation coding and vector quantization. In order to reduce the overhead in the commu...
详细信息
In this paper, a novel detection and recovery system is proposed for image authentication based on two compression schemes: block truncation coding and vector quantization. In order to reduce the overhead in the communication, the sender first compresses an image and then refines the characteristic values from the compressed image. The characteristic values are encrypted to digital signatures using the RSA scheme (proposed by Rivest, Shamir and Adleman). The signatures are embedded into the compressed image and thus the image integrity can be authenticated after transmission. Upon receipt of the compressed image, the receiver extracts the signatures and then decrypts the characteristic values using the sender's public key. Another characteristic value can also be decoded by the image compression scheme. By comparing a few characteristic values, the system determines whether or not the decompressed image is tampered and then outputs a correct characteristic value to rebuild the tampered regions. Furthermore, the proposed scheme authenticates the integrity of the image to the receiver and effectively recovers the tampered image.
In this paper, a new scheme for designing multilevel ETC coding is proposed. Optimal quantization can be obtained by selecting the quantization threshold with an exhaustive search. However, this requires an enormous a...
详细信息
In this paper, a new scheme for designing multilevel ETC coding is proposed. Optimal quantization can be obtained by selecting the quantization threshold with an exhaustive search. However, this requires an enormous amount of computation and is, thus impractical when we consider an exhaustive search for the multilevel ETC. In order to find a better threshold so that the average mean square error between the original and reconstructed images is a minimum, the genetic algorithm is applied. Comparison of the results of the proposed method with the exhaustive search reveal that the former method can almost achieve optimal quantization with much less computation than that required in the latter case.
This paper presents a modified block truncation coding (ETC) algorithm for image compression. Similar blocks in an image are merged into a cluster and represented with the cluster center. Each cluster center is then e...
详细信息
This paper presents a modified block truncation coding (ETC) algorithm for image compression. Similar blocks in an image are merged into a cluster and represented with the cluster center. Each cluster center is then encoded with a vision block truncation coding (VBTC) algorithm which uses a small set of predefined binary edge patterns to approximate the bit plane of the cluster center. Experimental results show that the computation efficiency of the proposed algorithm is significantly improved when compared to the original BTC. (C) 1998 Elsevier Science B.V. All rights reserved.
暂无评论