Fast Codebook Generation Using Pattern Based Masking Algorithm for Image Compression

Abstract

Vector Quantization (VQ) is a classical block coding technique used for image compression which achieves high compression using simple encoding and decoding process. Codebook generation is an important factor in VQ design, which directly influence computational cost and the quality of reconstructed image. Linde-Buzo-Gray (LBG) is considered as a state of art technique, which uses k-mean clustering algorithm for codebook design. Various optimization techniques are applied for searching the optimal codebook such as Bat Algorithm (BA), Particle swarm optimization (PSO), and Firefly Algorithm (FA). These algorithm suffers mainly with high time consumption due to unavailability of optimal solution in search space. This research proposes a novel approach, where peak values of the histogram are applied to predefined pattern masks to predict the image patterns for codebook design. From the experimental results, it is indicated that when compared with other algorithms, the proposed pattern based masking (PBM) algorithm requires less iterations and converges at a faster speed, particularly at the bitrates ≥ 0.375 without compromising on peak signal to noise ratio (PSNR) and structural similarity index measure (SSIM).

Compression of images with a mathematical approach based on sine and cosine equations and vector quantization (VQ)

“…In these experiments, the codebook sizes are set to 8, 16, 32, 64, 128, 256, 512, and 1024. Tables (1) to (5) show the PSNR index for different Bitrates for pentagonal images [36]. Evaluations show that the proposed method has a higher PSNR in the reconstruction of compressed images.…”

“…In the proposed method for image compression, a codebook is encoded as a member of the ISCA algorithm. Figure (6) shows three codebooks as three members of a metaheuristic algorithm.…”

“…𝑁 𝑏 𝑖=1 𝑁 𝐶 𝐽=1 (14) Any codebook or any member of the ISCA algorithm that minimizes the objective function is considered optimal as a codebook. For compression of images according to the code network of Figure (6), with the ISCA algorithm, the optimal codebook is found. Initially, several random codebooks are created as members of the proposed algorithm population.…”

“…Vector quantization (VQ) is technique of block coding which is used to compress an image. In this method, the use of encryption and a simple decryption process causes high-level compression [6]. Production of codebook is a vital factor in VQ compression that directly influences the computational cost and the reconstructed image's quality.…”

Fast Linde–Buzo–Gray (FLBG) Algorithm for Image Compression through Rescaling Using Bilinear Interpolation

“…To decrease the image's size for storage and transmission, it is necessary to compress the image for practical use. The real-time transmission of images restricts the image compression techniques as they require fast buffering and low computational complexity [1]. Conversely, compressing images for storing in memory has no restrictions.…”