scholarly journals Blocking Artifacts Reduction in Block based Discrete Cosine Transform Compressed Images

2012 ◽  
Vol 42 (6) ◽  
pp. 19-24
Author(s):  
Parmjeet Kaur ◽  
Poonam Sethi
Keyword(s):  
Discrete Cosine Transform ◽  
Blocking Artifacts ◽  
Cosine Transform ◽  
Compressed Images ◽  
Artifacts Reduction ◽  
Block Based

scholarly journals A Post-Processing Algorithm for Spatial Domain Detection & Removal of Alocking Artifacts

2019 ◽  
Vol 8 (10) ◽  
pp. 2968-2977
Keyword(s):  
Spatial Domain ◽  
Processing Algorithm ◽  
Blocking Artifacts ◽  
Post Processing ◽  
Compressed Images ◽  
Ringing Artifacts ◽  
Initial Stage ◽  
Pixel Value ◽  
Block Based ◽  
Processing Techniques

Block based Discrete Cosine Transform (BDCT) is commonly used to detect and remove blocking artifacts in the compressed images. We proposed spatial domain post processing algorithm with four fold model. In the initial stage, pixel vector (PV) is calculated for horizontal as well as vertical block boundaries, after defining PV calculation of different threshold values is made for extracting blocking artifacts. These thresholds are basically adaptive to the image quality due to strong correlation with the PV. To avoid ringing artifacts across block edges directional filter is proposed. Our research further worked on region classification based upon activity of PV within the blocks. Based upon different PV activity regions separate filters are used to achieve best filtering and finally Symmetrical Pixel Normalization filter (SPN Filter) is used to normalize the values of symmetrical pixel value for better visual performance . Proposed technique various indices like PSNR, MSSIM, GBIM are calculated and compare with different post processing techniques used in literature

scholarly journals Estimating Previous Quantization Factors on Multiple JPEG Compressed Images

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Sebastiano Battiato ◽  
Oliver Giudice ◽  
Francesco Guarnera ◽  
Giovanni Puglisi
Keyword(s):  
Image Quality ◽  
Discrete Cosine Transform ◽  
Jpeg Compression ◽  
Compression Algorithm ◽  
Experimental Results ◽  
The Other ◽  
Cosine Transform ◽  
Novel Technique ◽  
Compressed Images ◽  
Acquisition Device

AbstractThe JPEG compression algorithm has proven to be efficient in saving storage and preserving image quality thus becoming extremely popular. On the other hand, the overall process leaves traces into encoded signals which are typically exploited for forensic purposes: for instance, the compression parameters of the acquisition device (or editing software) could be inferred. To this aim, in this paper a novel technique to estimate “previous” JPEG quantization factors on images compressed multiple times, in the aligned case by analyzing statistical traces hidden on Discrete Cosine Transform (DCT) histograms is exploited. Experimental results on double, triple and quadruple compressed images, demonstrate the effectiveness of the proposed technique while unveiling further interesting insights.

Sign in / Sign up

Export Citation Format

Share Document