scholarly journals Color Image Transcoding of Lossless Encoder and Standard Lossy Decoder based on JP2K

1970 ◽  
Vol 8 (2) ◽  
pp. 113-121
Author(s):  
Suvit Poomrittigul ◽  
Masahiro Iwahashi
Keyword(s):  
Wavelet Transform ◽  
Discrete Wavelet Transform ◽  
Color Image ◽  
Discrete Wavelet ◽  
Rounding Error ◽  
Image System ◽  
Scaling Parameter ◽  
Lossless Coding ◽  
Color Transform

In JPEG2000 (JP2K) color image system, loss less coding signal is not able to be reconstructed with lossy decoder directly. Then, this report proposes a new transcoding between lossless encoder and standard lossy decoder for color image signals base on JP2K. A proposed encoder is required reversible color transform (RCT) and reversible discrete wavelet transform (RDWT) with compatibility to standard lossy decoder based on JP2K (JP2K lossy decoder). To improve the compatibility, proposed encoder is designed by using Non-scaled RCT and Non-Scaled RDWT with embedding scaling parameter into quantization header. Then, this method can be practical use with JP2K lossy decoder without any change. It also reduces total rounding error and lifting steps. The results show that proposed method can keep lossless coding performance and improve transcoding functionality to JP2K lossy decoder. The quality of transcoding image was achieved to 50.05 dB (PSNR).

An Adaptive Binarization Method for Cost-efficient Document Image System in Wavelet Domain

2020 ◽  
Vol 64 (3) ◽  
pp. 30401-1-30401-14 ◽  
Author(s):  
Chih-Hsien Hsia ◽  
Ting-Yu Lin ◽  
Jen-Shiun Chiang
Keyword(s):  
Wavelet Transform ◽  
Discrete Wavelet Transform ◽  
Document Image ◽  
Background Information ◽  
Raspberry Pi ◽  
Discrete Wavelet ◽  
Image System ◽  
Low Frequencies ◽  
Cost Efficient ◽  
Binarization Method

Abstract In recent years, the preservation of handwritten historical documents and scripts archived by digitized images has been gradually emphasized. However, the selection of different thicknesses of the paper for printing or writing is likely to make the content of the back page seep into the front page. In order to solve this, a cost-efficient document image system is proposed. In this system, the authors use Adaptive Directional Lifting-Based Discrete Wavelet Transform to transform image data from spatial domain to frequency domain and perform on high and low frequencies, respectively. For low frequencies, the authors use local threshold to remove most background information. For high frequencies, they use modified Least Mean Square training algorithm to produce a unique weighted mask and perform convolution on original frequency, respectively. Afterward, Inverse Adaptive Directional Lifting-Based Discrete Wavelet Transform is performed to reconstruct the four subband images to a resulting image with original size. Finally, a global binarization method, Otsu’s method, is applied to transform a gray scale image to a binary image as the output result. The results show that the difference in operation time of this work between a personal computer (PC) and Raspberry Pi is little. Therefore, the proposed cost-efficient document image system which performed on Raspberry Pi embedded platform has the same performance and obtains the same results as those performed on a PC.

Hybrid Color Image Compression Using Discrete Cosine Transform and Discrete Wavelet Transform

2012 ◽  
Vol 198-199 ◽  
pp. 244-248 ◽  
Author(s):  
Ling Tang ◽  
Ming Ju Chen ◽  
Hong Song
Keyword(s):  
Wavelet Transform ◽  
Image Compression ◽  
Discrete Wavelet Transform ◽  
Discrete Cosine Transform ◽  
Color Image ◽  
Low Frequency ◽  
Huffman Coding ◽  
Discrete Wavelet ◽  
Cosine Transform ◽  
Color Image Compression

In this research we undertake a study of image compression based on the discrete cosine transform(DCT) and discrete wavelet transform(DWT). Then a hybrid color image compression algorithm based on DCT and DWT is proposed. This algorithm is implemented through transform the color image using DWT in the YCbCr space first, and then DCT in the low frequency, adopt huffman coding, RLE and arithmetic coding in the encoded mode. In experiments, the results outperform the only DCT and the only DWT typically higher in peak signal-to-noise ratio and have better visual quality.

scholarly journals SELECTED ASPECTS IN THE ANALYSIS OF THE COMBUSTION PROCESS USING WAVELET TRANSFORM

2020 ◽  
Vol 10 (3) ◽  
pp. 52-55
Author(s):  
Żaklin Grądz
Keyword(s):  
Wavelet Transform ◽  
Discrete Wavelet Transform ◽  
Sampling Rate ◽  
Combustion Process ◽  
Measurement Data ◽  
Combustion Products ◽  
Discrete Wavelet ◽  
Direct Influence ◽  
High Sampling Rate

The complexity of changes occurring in the flame during the combustion process has a direct influence on the quantity and quality of the combustion products. The presented measurement data pertaining to the changes in flame luminosity were recorded using a specialized monitoring system. These signals from the combustion of such fuels as pulverized coal and mazout were recorded with high sampling rate. The paper presented the analysis of changes in flame luminosity for different fuels using continuous and discrete wavelet transform. The main aim of the studies was to determine the scale values, which enable differentiating between the type of combusted fuel. The results of studies were presented in the form of scalograms.

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