scholarly journals New Image Compression Algorithm using Haar Wavelet Transform

Author(s):  
R. El Ayachi ◽  
B. Bouikhalene ◽  
M. Fakir

<p>The compression is a process of Image Processing which interested to change the information representation in order to reduce the stockage capacity and transmission time. In this work we propose a new image compression algorithm based on Haar wavelets by introducing a compression coefficient that controls the compression levels. This method reduces the complexity in obtaining the desired level of compression from the original image only and without using intermediate levels.</p>

Author(s):  
Harbi S. Jamila ◽  
Batool Daraam ◽  
Waseem M. Ali

Some image processing applications like segmentation need effective techniques that work as edge detection and extraction, many filters in this field fail to achieve the desired result and consequently the further processing fails, so it is needed sometimes to modify a technique to work in robust and effective way. In ultrasound, although it is a common and real-time non-destructive test methods, but processing and analyzing such images require special filters and modifications to overcome some weakness sides in this field, especially when scanning objects comparable to the acoustic wavelength. In this paper, two modified filters were suggested, first one is two-step unsharp filter, in this techniques the image was enhanced twice the first time the edges that extracted from the original scaled image where added back to the image, and in the second time the same edges were added to the scaled enhanced image. The second technique is summarized as adding back the Low-High and High-Low bands that were extracted previously from the original image by Haar wavelet transform to the image which reinforce its edges.


2018 ◽  
Vol 14 (10) ◽  
pp. 94
Author(s):  
Xianfeng Yang ◽  
Xiaojian Jia

<span style="font-family: 'Times New Roman',serif; font-size: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-fareast-language: DE; mso-ansi-language: EN-US; mso-bidi-language: AR-SA;">With multi-frame image processing based on wireless sensor network as research object, this study analyzes the problems existing in the two classic multi-node collaborative distributed image processing algorithms based on wavelet transform using literature analysis, simulation experiment, data analysis and other research methods, proposes a distributed image compression algorithm based on SHIHT with the application of wireless sensor network, SPIHT algorithm and wavelet transform to image compression as theoretical foundations, and adopts the matrix laboratory to simulate the energy performance of the algorithm. Through comparative analysis, the feasibility of distributed image compression algorithm based on SHIHT presented in this study is verified.</span>


2013 ◽  
Vol 464 ◽  
pp. 411-415
Author(s):  
Jin Cai ◽  
Shuo Wang

JPEG 2000 is a new image coding system that uses state-of-the-art compression techniques based on wavelet technology. As interactive multimedia technologies evolve, the requirements for the file format used to store the image data continue to evolve. The size and bit depth collected for an image to increase the resolution and extend the dynamic range and color gamut. Discrete Wavelet transform based embedded image coding method is the basis of JPEG2000. Image compression algorithm for the proper use and display of the image is a requirement for digital photography.


2017 ◽  
Vol 4 (3) ◽  
pp. 238-247
Author(s):  
Nobuyuki Umezu ◽  
Keisuke Yokota ◽  
Masatomo Inui

Abstract Most of workpiece shapes in NC milling simulations are in Z-map representations that require a very large amount of data to precisely hold a high resolution model. An irreversible compression algorithm for Z-map models using a two-dimensional Haar wavelet transform is proposed to resolve this tight memory situation for an ordinary PC. A shape model is first transformed by using Haar wavelet to build a wavelet synopsis tree while the maximum errors caused by virtually truncating high-frequency components are simultaneously calculated. The total amount of the shape data can be reduced by truncating particular sections of the wavelet components that satisfy the error threshold given by the user. Our algorithm guarantees that any error due to its irreversible compression processes is smaller than the specified level measured against the original model. A series of experiments were conducted using an Apple iMac with a 3.2 GHz CPU and 8 GB of memory. The experiments were performed with 16 sample shape models on 512×512 to 8192×8192 grids to evaluate the compression efficiency of the proposed method. Experimental results confirmed that our compression algorithm requires approximately 20–30 ms for 512×512 models and 7 s for 8192×8192 models under a maximum error level of 10× 10−6 m (a typical criteria for NC milling simulations). The compressed binaries outputted by the proposed method are generally 25–35% smaller than the baseline results by gzip, one of common reversible compression libraries, while these two methods require almost the same level of computational costs. Highlights Discarding diagonal components in WT significantly reduces data amount. The proposed method outperforms a reversible method by 25–35% in size reduction. Most of computational time is consumed by the reversible compression step. The proposed method compresses 5122 models in 20 ms, 81922 models in 7 s.


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