A high quality image compression technique for low cost multimedia applications

1995 ◽  
Vol 41 (1) ◽  
pp. 140-149 ◽  
Author(s):  
P.W.M. Tsang
2011 ◽  
Vol 11 (03) ◽  
pp. 355-375 ◽  
Author(s):  
MOHAMMAD REZA BONYADI ◽  
MOHSEN EBRAHIMI MOGHADDAM

Most of image compression methods are based on frequency domain transforms that are followed by a quantization and rounding approach to discard some coefficients. It is obvious that the quality of compressed images highly depends on the manner of discarding these coefficients. However, finding a good balance between image quality and compression ratio is an important issue in such manners. In this paper, a new lossy compression method called linear mapping image compression (LMIC) is proposed to compress images with high quality while the user-specified compression ratio is satisfied. This method is based on discrete cosine transform (DCT) and an adaptive zonal mask. The proposed method divides image to equal size blocks and the structure of zonal mask for each block is determined independently by considering its gray-level distance (GLD). The experimental results showed that the presented method had higher pick signal to noise ratio (PSNR) in comparison with some related works in a specified compression ratio. In addition, the results were comparable with JPEG2000.


2017 ◽  
Vol 11 (10) ◽  
pp. 899-909 ◽  
Author(s):  
Vikrant Singh Thakur ◽  
Shubhrata Gupta ◽  
Kavita Thakur

Author(s):  
Rana J.S. Al-janabi ◽  
Shroouq J.S. Al-janabi ◽  
Zinah Hussein Toman

Recently, information transmission is done electronically, information can be stored and manipulated easily using computer, information transferring should be done in secure way. Watermark is a technique that can be used to secure data. In this paper, a new watermark algorithm is proposed which depends on integer wavelet transform, arithmetic encoding and adaptive run length encoding. Adaptive run length encoding is used to compress watermark before embedding process. Arithmetic encoding can be used to compress data in original image that are needed to be retrieved from watermarked images to recover original image without any differences after watermark extraction process. To avoid the problem of traditional Run Length Encoding Technique that may produce file that is larger than original one. Adaptive run length encoding is suggested which is used to compress watermark in cover image. The adaptive compression technique can be done several times on watermark using different number of bits to represent counts of runs and produce several vectors for number of runs, compare several results and select smallest vector from them. Surely, the smallest vector means that watermarked image will be high quality image; capacity will be better and adaptively ensure embedding process will be more secure.


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