Image Compression Algorithm Research Articles

Fast Full-Search Algorithm of Fractal Image Compression for Acceleration Image Processing

A new processing algorithm based on fractal image compression is proposed for image processing efficiency. An image will partition into non-overlapping blocks called range blocks and overlapping blocks called domain blocks, with the domain blocks generally bigger than the range blocks, to achieve a rapid encoding time. This research introduced a new fast full-search algorithm approach that starts the search for the best matching domain in the range block from the closest points in the range blocks and expands the search until an acceptable match is found or the search is completed to save even more encoding time. The proposed fast full-search approach, despite its simplicity, is more efficient than the standard search method. The search reduction, peak signal to noise ratio, compression ratio, and encoding time of the suggested approach are all examined. The proposed method can encode a 512x512 grayscale Lena image in 0.36 seconds, with a total search reduction of 87% according to experimental results.

Curvelet Transform Based Compression Algorithm for Low Resource Hyperspectral Image Sensors

The wavelet transform is widely used in the task of hyperspectral image compression (HSIC). They have achieved outstanding performance in the compression of a hyperspectral (HS) image, which has attracted great interest. However, transform based hyperspectral image compression algorithm (HSICA) has low-coding gain than the other state of art HSIC algorithms. To solve this problem, this manuscript proposes a curvelet transform based HSIC algorithm. The curvelet transform is a multiscale mathematical transform that represents the curve and edges of the HS image more efficiently than the wavelet transform. The experiment results show that the proposed compression algorithm has high-coding gain, low-coding complexity, at par coding memory requirement, and works for both (lossy and lossless) compression. Thus, it is a suitable contender for the compression process in the HS image sensors.

Image compression and encryption algorithm based on uniform non-degeneracy chaotic system and fractal coding

Image compression and encryption algorithm based on uniform non-degeneracy chaotic system and fractal coding

Image and video compression of fluid flow data

We study the compression of spatial and temporal features in fluid flow data using multimedia compression techniques. The efficacy of spatial compression techniques, including JPEG and JPEG2000 (JP2), and spatiotemporal video compression techniques, namely H.264, H.265, and AV1, in limiting the introduction of compression artifacts and preserving underlying flow physics are considered for laminar periodic wake around a cylinder, two-dimensional turbulence, and turbulent channel flow. These compression techniques significantly compress flow data while maintaining dominant flow features with negligible error. AV1 and H.265 compressions present the best performance across a variety of canonical flow regimes and outperform traditional techniques such as proper orthogonal decomposition in some cases. These image and video compression algorithms are flexible, scalable, and generalizable holding potential for a wide range of applications in fluid dynamics in the context of data storage and transfer.Graphic abstract

VLSI Design Based on Block Truncation Coding for Real-Time Color Image Compression for IoT.

It has always been a major issue for a hospital to acquire real-time information about a patient in emergency situations. Because of this, this research presents a novel high-compression-ratio and real-time-process image compression very-large-scale integration (VLSI) design for image sensors in the Internet of Things (IoT). The design consists of a YEF transform, color sampling, block truncation coding (BTC), threshold optimization, sub-sampling, prediction, quantization, and Golomb-Rice coding. By using machine learning, different BTC parameters are trained to achieve the optimal solution given the parameters. Two optimal reconstruction values and bitmaps for each 4 × 4 block are achieved. An image is divided into 4 × 4 blocks by BTC for numerical conversion and removing inter-pixel redundancy. The sub-sampling, prediction, and quantization steps are performed to reduce redundant information. Finally, the value with a high probability will be coded using Golomb-Rice coding. The proposed algorithm has a higher compression ratio than traditional BTC-based image compression algorithms. Moreover, this research also proposes a real-time image compression chip design based on low-complexity and pipelined architecture by using TSMC 0.18 μm CMOS technology. The operating frequency of the chip can achieve 100 MHz. The core area and the number of logic gates are 598,880 μm2 and 56.3 K, respectively. In addition, this design achieves 50 frames per second, which is suitable for real-time CMOS image sensor compression.

Quantum color image compression and encryption algorithm based on Fibonacci transform

Quantum color image compression and encryption algorithm based on Fibonacci transform

Image Compression Network Structure Based on Multiscale Region of Interest Attention Network

In this study, we proposed a region of interest (ROI) compression algorithm under the deep learning self-encoder framework to improve the reconstruction performance of the image and reduce the distortion of the ROI. First, we adopted a remote sensing image cloud detection algorithm for detecting important targets in images, that is, separating the remote sensing background from important regions in remote sensing images and then determining the target regions because most traditional ROI-based image compression algorithms utilize the manual labeling of the ROI to achieve region separation in images. We designed a multiscale ROI self-coding network from coarse to fine with a hierarchical super priority layer to synthesize images to reduce the spatial redundancy more effectively, thus greatly improving the distortion rate performance of image compression. By using a spatial attention mechanism for the ROI in the image compression network, we achieved better compression performance.

Swarm and Evolutionary Algorithms in Image Compression by F-Transform

This article investigates the application of swarm and evolutionary algorithms, namely the SOMA, DE, and GA, for optimizing the F-transform-based image compression. To do this, we introduce the cost function, evaluating the approximation of decompressed image to the original image, concerning the parameters that control the approximation quality of the F-transform. This function is then minimized by the selected algorithms to find optimal settings for image compression and decompression. We design experiments to compare the performance of the original F-transform method and the methods optimized by SOMA, DE, and GA on a dataset of 10 pictures. In all considered cases, the results obtained with the optimized method completely surpass those obtained by the original one. We also apply a statistical test (called Wilcoxon signed-rank test) for ranking the performance of selected algorithms in this issue. The results show that the SOMA and DE perform well in cases where the compressed image sizes are small. However, the GA algorithm shows outperformance in comparison with the others in more complicated cases where the compressed image size is bigger. The outperformance of the GA is in terms of decompression quality and computation time. Finally, we provide a visual comparison between the original F-transform-based method and the method optimized by the GA, tested on a 128×128 picture. The decompressed image by the latter is much sharper and more detailed than that obtained by the former.

Compression of mri images with brain pathology based on Haaar wavelet

Currently wavelets are widely used in various fields related to the processing and analysis of signals and images. One application is the task of image compression. The advantage of compression using wavelet algorithms is that they work with the entire image and not with its individual blocks. At high compression ratios this avoids a block structure. This paper analyzes the effectiveness of the compression algorithm for medical MRI images with brain pathology which is based on the Haar wavelet transform. Implementation effective compression methods will allow storing a larger number of patient tomograms on a central server without increasing storage volumes. Experiments were performed and the dependences of indicators for assessing the quality of compressed MRI images on the compression ratio were constructed. The algorithm with zeroing wavelet coefficients by a threshold showed a better result compared to zeroing by levels based on assessing the quality of a compressed MRI image using a set of corresponding metrics.

Hyperspectral Image Compression via Cross-Channel Contrastive Learning

In recent years, advances in deep learning have greatly promoted the development of hyperspectral image (HSI) compression algorithms. However, most existing compression approaches directly rely on rate-distortion optimization without other guidance during model learning. Therefore, this brings challenges to distinguishing similar features or objects that are widely available in HSIs, especially in remote sensing scenes, since quantification in lossy compression can cause informative attribute (e.g., category) collapse and loss problems at high compression ratios. In this paper, we propose a novel hyperspectral compression network via contrastive learning (HCCNet) to help generate discriminative representations and preserve informative attributes as much as possible. Specifically, we design a contrastive informative feature encoding (CIFE) to extract and organize discriminative attributes from the original HSIs by enlarging the discrimination over the learned latents in different channel indexes to relieve attribute collapses. In the case of attribute losses, we define a contrastive invariant feature recovery (CIFR) to discover the lost attributes via contrastive feature refinement. Experiments on five different HSI datasets illustrate that the proposed HCCNet can achieve impressive compression performance, such as improvement of the peak signal-to-noise ratio (PSNR) from 28.86 dB (at 0.2284 bpppb) to 30.30 dB (at 0.1960 bpppb) on the Chikusei dataset.

Improving Image Compression With Adjacent Attention and Refinement Block

Recently, learned image compression algorithms have shown incredible performance compared to classic hand-crafted image codecs. Despite its considerable achievements, the fundamental disadvantage is not optimized for retaining local redundancies, particularly non-repetitive patterns, which have a detrimental influence on the reconstruction quality. This paper introduces the autoencoder-style network-based efficient image compression method, which contains three novel blocks, i.e., adjacent attention block, Gaussian merge block, and decoded image refinement block, to improve the overall image compression performance. The adjacent attention block allocates the additional bits required to capture spatial correlations (both vertical and horizontal) and effectively remove worthless information. The Gaussian merge block assists the rate-distortion optimization performance, while the decoded image refinement block improves the defects in low-resolution reconstructed images. A comprehensive ablation study analyzes and evaluates the qualitative and quantitative capabilities of the proposed model. Experimental results on two publicly available datasets reveal that our method outperforms the state-of-the-art methods on the KODAK dataset (by around 4dB and 5dB) and CLIC dataset (by about 4dB and 3dB) in terms of PSNR and MS-SSIM.

ANALYSIS OF THE POSSIBILITY OF USING THE SINGULAR VALUE DECOMPOSITION IN IMAGE COMPRESSION

In today’s highly computerized world, data compression is a key issue to minimize the costs associated with data storage and transfer. In 2019, more than 70% of the data sent over the network were images. This paper analyses the feasibility of using the SVD algorithm in image compression and shows that it improves the efficiency of JPEG and JPEG2000 compression. Image matrices were decomposed using the SVD algorithm before compression. It has also been shown that as the image dimensions increase, the fraction of eigenvalues that must be used to reconstruct the image in good quality decreases. The study was carried out on a large and diverse set of images, more than 2500 images were examined. The results were analyzed based on criteria typical for the evaluation of numerical algorithms operating on matrices and image compression: compression ratio, size of compressed file, MSE, number of bad pixels, complexity, numerical stability, easiness of implementation.

Medical Image Compression Based on Variational Autoencoder

With the rapid growth of medical image data, it has become a current research hotspot that how to realize the large amounts of the real-time upload and storage of medical images with limited network bandwidth and storage space. However, currently, medical image compression technology cannot perform joint optimization of rate (the degree of compression) and distortion (reconstruction effect). Therefore, this study proposed a medical image compression algorithm based on a variational autoencoder. This algorithm takes rate and distortion as the common optimization goal and uses the residual network module to directly transmit information, which alleviates the contradiction between improving the degree of compression and optimizing the reconstruction effect. At the same time, the algorithm also reduces image loss in the medical image compression process by adding the residual network. The experimental results show that, compared with the traditional medical image compression algorithm and the deep learning compression algorithm, the algorithm in this study has smaller distortion, better reconstruction effect, and can obtain higher quality medical images at the same compression rate.

Perceptual quality assessment for fine-grained compressed images

Recent years have witnessed the rapid development of image storage and transmission systems, in which image compression plays an important role. Generally speaking, image compression algorithms are developed to ensure good visual quality at limited bit rates. However, due to the different compression optimization methods, the compressed images may have different levels of quality, which needs to be evaluated quantificationally. Nowadays, the mainstream full-reference (FR) metrics are effective to predict the quality of compressed images at coarse-grained levels (the bit rates differences of compressed images are obvious), however, they may perform poorly for fine-grained compressed images whose bit rates differences are quite subtle. Therefore, to better improve the Quality of Experience (QoE) and provide useful guidance for compression algorithms, we propose a full-reference image quality assessment (FR-IQA) method for compressed images of fine-grained levels. Specifically, the reference images and compressed images are first converted to YCbCr color space. The gradient features are extracted from regions that are sensitive to compression artifacts. Then we employ the Log-Gabor transformation to further analyze the texture difference. Finally, the obtained features are fused into a quality score. The proposed method is validated on the fine-grained compression image quality assessment (FGIQA) database, which is especially constructed for assessing the quality of compressed images with close bit rates. The experimental results show that our metric outperforms mainstream FR-IQA metrics on the FGIQA database. We also test our method on other commonly used compression IQA databases and the results show that our method obtains competitive performance on the coarse-grained compression IQA databases as well.

A reliable image compression algorithm based on block luminance adopting deep learning for video surveillance application

Video surveillance systems are essential as other application domain. Handling efficient and reliable for underground projects as well surveillance image is so significant to ensure security and safety. The wireless channels are efficient as data transferring media. On the other hand, the bandwidth may be limited for some environmental conditions. Hence, the image compression algorithm is very important to be conducted and applied to save the transmission bandwidth. This paper presents an image compression algorithm for video surveillance. The method is based on the concept of luminance variation of image. The image compression method is expected to achieve a reasonable compression ratio with acceptable quality. With another meaning, the compressed image size is decreased and consumes a smaller transmission bandwidth via the wireless channel compared with the original image size. The method adopts a deep learning approach to improve the quality with limited bandwidth. The proposed method is abbreviated as DLBL (deep learning block luminance). DLBL implemented and tested on some tested bed images. The performance of the proposed method is compared with some ones considering the same conditions. Some measurable criteria are taken into consideration for performance evaluation. The criteria are the compression ratio (CR), peak signal-to-noise ratio (PSNR) and structure similarity index measure (SSIM). From the experiments results, the proposed method showed significant and efficient performance compared with some other related ones. This is clear from the values of CR, PSNR and SSIM.

Image buffering in application specific processors

In many digital image-processingapplications, which are implementedin field programmable gate arrays,the currently processed image's frames are stored in external dynamic memory.The performance of such an application dependson the dynamic memoryspeed and the necessaryrequests quantity during algorithm’sruntime. This performance is being optimized through field programmable gate arrays -implemented buffer memory usage.But there is no common method for the formal buffer memory synthesis with preset throughput, input and output data sequenceorderand minimizedhardwarecosts.In this article,the featuresof image input and processing based on Field Programmable Gate Arrayareconsidered.The methods of building buffer circuits in field programmable gate arrays, due to which the intensity of data exchanges with external memory is reduced, are analyzed. Themethod of synthesizing pipeline circuits with specified performance characteristics and the data sequence order is given, which is based on the mapping of the spatial synchronous data flows into the structure implemented in the field programmable gate arrays.A method of designing buffer schemes is proposed, which is based on the mapping of spatial synchronous data flows into local memory in the form of chains of pipeline registers.The method helpsto organize the data flow of at the input of built-in pipeline units of image processing, in which the data follow in a given order, andto minimize the amount of buffer memory.The method ensures the use of dynamically adjustable register delays built into the field programmable gate arrays, which increases the efficiency of buffering.Thismethod was tested during the development of an intelligent video camera. The embedded hardware implements a video image compression algorithm with a wide dynamic range according to the Retinexalgorithm. The same time it selects characteristic points in the image for the further pattern recognition.At the same time, multiple decimation of the frame is performed. Due to themultirate buffering of the image in the field programmable gate arrays,it was possible to avoid using of external dynamic memory.

Methods and Algorithms for Image Compression Based on Machine Learning

Methods and Algorithms for Image Compression Based on Machine Learning

A Lévy Flight Based BAT Optimization Algorithm for Block-based Image Compression

Many metaheuristics have been adopted to solve the codebook generation problem in image processing. In this paper, the Bat algorithm is combined by the Lévy flight distribution to find out the global optimum codebook. The Lévy flight distribution is combined by the local search procedure. Therefore most of the time the bat concentrate on the local area for specific food while it rarely flies to the different parts of the field for better food opportunities. This process strongly guides the bat on the global minimum way and offers better food, then the bat flies to that direction. Consequently, if a bat is captured by a local minimum point accidentally, the Lévy flight step provides a chance to escape from it easily. Numerical results suggest that the proposed Lévy flight based Bat algorithm is better than the classical ones and provides the global optimum codebook for image compression.

End-to-end deep multispectral image compression based on interspectral prediction network

Multispectral images have numerous features and a wide range of applications. However, traditional image compression methods, such as JPEG2000 and 3D-SPIHT, do not make effective use of spectral information. We propose a deep compression framework based on interspectral prediction to take full advantage of spectral correlation when using temporal correlation for interframe prediction in video compression. First, two-dimensional and three-dimensional convolutions were used to obtain spatial and spectral information for predicting the original image. Then, we applied a residual neural network to compress the residual information of the image. Subsequently, a decoder was employed to reconstruct the multispectral image based on the compressed image and residual information. All components were jointly trained by a single loss function that considered the tradeoff between the compression bit rate and decoded image quality. The experimental results showed that our proposed method outperformed other traditional compression algorithms, including JPEG2000, 3D-SPIHT, and PCA+JPEG2000, in terms of peak signal-to-noise ratio and spectral angle and is equivalent to or even better than some image compression algorithms based on deep neural networks.

A joint image compression and encryption algorithm based on compression sensing and bit-plane embedding

In medical, financial and other fields, the direct transmission of digital images in public channels is vulnerable to attacks and information leakage. In order to solve such problems, this paper proposes a new one-dimensional chaotic map. The information hiding visual security algorithm is based on the chaotic sequence diffusion image and bit plane decomposition technology, which greatly improves the visual security of the embedded image, and its structure and vision maintain a high degree of similarity with the carrier image. Firstly, a new one-dimensional chaotic map is proposed. The generated key stream can improve the randomness of the algorithm. Secondly, we optimize the measurement matrix to reduce the minimum coherence between the matrices and improve the reconstruction performance. Then we obtain the intermediate state cipher image through compression and encryption, and then embed the intermediate state cipher image by decomposing the carrier image bit plane, and finally obtain a visual security image. The experimental results show that, compared with the existing related literature, the algorithm has better reconstruction performance, security performance and operational efficiency.