JPEG Adapted quantization matrix for low vision viewers

1 .K . SivakamiSundari, Professor, IT Department, PSNA College of Engineering and Technology, Dindigul624622,Email:[email protected] 2 .Dr.V. Sadasivam, Professor &Head, CSE Department,Manonmanium Sundaranar University,Tirunelveli Email:[email protected] ABSTRACT Image enhancement algorithm for low vision viewers was developed. The current work sharpens the compressed images in the Discrete Cosine Transform domain. People with reduced visual acuity have difficulties in reading small prints, or in viewing the decompressed images with blocking artifacts. Blocking artifacts represents the high frequency components of the image. High-frequency characteristics of the image are enhanced by suitably scaling each element of the encoding quantisation table. Instead of the original table, either the modified table is transmitted or the corresponding mathematical model is to be kept at the receiver. In addition to the advantages of compression, the added feature is the level of enhancement is an adjustable one at the receiver or by end user. Compression of the twodimensional signal without much loss can be achieved with JPEG. Proposed algorithm modifies the JPEG Quantisation table so that the horizontal direction contrast is enhanced rather than the vertical direction contrast. Results show that this compressed domainfiltering algorithm performs better than the spatial filtering techniques.