  Measurement of image quality is very crucial to many image processing
applications. Quality metrics are used to measure the quality of improvement in
the images after they are processed and compared with the original images.
Compression is one of the applications where it is required to monitor the
quality of decompressed or decoded image. JPEG compression is the lossy
compression which is most prevalent technique for image codecs. But it suffers
from blocking artifacts. Various deblocking filters are used to reduce blocking
artifacts. The efficiency of deblocking filters which improves visual signals
degraded by blocking artifacts from compression will also be studied. Objective
quality metrics like PSNR, SSIM, and PSNRB for analyzing the quality of
deblocked images will be studied. We introduce a new approach of PSNR-B for
analyzing quality of deblocked images. Simulation results show that new
approach of PSNR-B called modified PSNR-B. it gives even better results
compared to existing well known blockiness specific indices
