OWING TO PERSONAL COMPUTERS BEING APPLIED INMANY FIELDS, MOST INFORMATION IS TRANSMITTED WITH DIGITAL FORMAT SUCH AS TEXT DOCUMENTS, AUDIO, IMAGES AND VIDEOS. WITH THE RAPID GROWTH OF THE INTERNET AND THE DEVELOPMENT OF MULTIMEDIA NETWORK SYSTEM , ILLEGAL COPYING, TAMPERING, MODIFYING AND COPYRIGHT PROTECTION HAVE BECOME VERY IMPORTANT ISSUES AND THAT IS A CHALLENGING TASK TO PROTECT COPYRIGHT OF AN INDIVIDUAL IS CREATION. SO, THERE IS GREAT NEED OF PROHIBITING SUCH ILLEGAL COPYRIGHT OF DIGITAL MEDIA. DIGITAL WATERMARKING PROVIDES A VIABLE SOLUTION TO PROTECT COPYRIGHT AND ACKNOWLEDGE THE OWNERSHIP OF AN INTELLECTUAL PROPERTY. IN THIS PAPER, WE PROPOSE A METHOD OF NON-BLIND TRANSFORM DOMAIN WATERMARKING BASED ON DWT-DCT. IT PERFORMS 3 LEVEL DWT OF ORIGINAL (COVER) IMAGE AND THEN WATERMARK IMAGE WOULD BE EMBEDDED IN THE MIDDLE-COEFFICIENTS OF DCT TRANSFORMED OF SUBBANDS( LL3) OF COVER IMAGE. THE PARAMETERS USED TO TEST THE ROBUSTNESS AND TRANSPARENCY OF THE PROPOSED ALGORITHM IS THE PEAK SIGNAL TO NOISE RATIO (PSNR) AND SIMILARITY RATE (SR). EXPERIMENTAL RESULTS SHOW THAT COMBINING THE TWO TRANSFORMS IMPROVED THE PERFORMANCE OF THE WATERMARKING ALGORITHM. MOREOVER, THIS METHOD PROVIDES HIGH IMPERCEPTIBILITY AS WELL AS HIGH ROBUSTNESS AGAINST DIFFERENT ATTACKS SUCH AS JPEG COMPRESSION, GAUSSIAN NOISE, SALT & PEPPER NOISE, ETC. ...

IN THIS PAPER A CORDIC BASED APPLICATION-SPECIFIC INSTRUCTION-SET PROCESSOR (ASIP) FOR TWO DIMENSIONAL DISCRETE FOURIER TRANSFORM (DFT) AND DISCRETE COSINE TRANSFORM (DCT) IS PROPOSED. TODAY, DFT PERFORMS AN IMPORTANT ROLE IN DIGITAL SIGNAL PROCESSING, AND DCT ALGORITHM IS SUITABLE FOR IMAGE COMPRESSION APPLICATIONS. USING CORDIC METHOD INSIDE THESE TWO SIGNAL PROCESSING ALGORITHMS REDUCES THE NUMBER OF MEMORY ACCESSES. ASIP CAN ACT AS AN ALTERNATIVE TO ASIC AND GPP DESIGN IF IT DOES SATISFY THE CRITICAL POINTS OF POWER CONSUMPTION, TOTAL DELAY, MANUFACTURING COST AND PRODUCTIVITY OF THOSE DESIGNS. FURTHERMORE, FOR SATISFYING THESE PARAMETERS, TWO STAGE OF UTILIZATION IS PERFORMED ON THE BASIC MANO MODEL. AS A MATER OF FACT, TEMPORARY REGISTERS AND DATA BUS ARE IMPROVED, RAM AND CACHE MEMORY ARE ADDED, AND THE NUMBER OF FUNCTIONAL UNITS IS INCREASED. AS A RESULT THE NUMBER OF GATES IN THE CONTROL UNIT IS DECREASED ABOUT 84% IN THE DFT AND 86% IN THE DCT IN COMPARISON TO THE MANO DESIGN. MOREOVER, THE DFT AND THE DCT INSTRUCTIONS IN THIS DESIGN CONSUME 3.6% AND 3.86% AS THE NUMBER OF CLOCKS AS THE MANO DESIGN DOES. UTILIZATION IN THE PROPOSED PIPELINE ARCHITECTURE IS EVALUATED WITH REGISTER TRANSFER LANGUAGE (RTL) CODES.

IMAGE WATERMARKING IN DCT DOMAIN HAS A HIGH COMPUTATIONAL COMPLEXITY ESPECIALLY FOR COLOR AND HIGH RESOLUTION IMAGES, WHERE USAGE OF THEM HAS BEEN SIGNIFICANTLY GROWN. TO ADDRESS THIS ISSUE, IN THIS ARTICLE, A DATA-PARALLEL COLOR DCT WATERMARKING APPROACH IS PROPOSED AND IMPLEMENTED ON GPU USING CUDA. ALSO, IN THIS WORK, BEFORE EMBEDDING, THE COLOR WATERMARK IS COMPRESSED USING A MODIFIED METHOD TO GET LESS DISTORTION. CUDA IMPLEMENTATION OF 8×8 DCT OFFERS 12X-43X SPEEDUP WITH GT 540M AND 94X-105X SPEEDUP WITH GTX 580, FOR DIFFERENT IMAGE SIZES. IN CASE OF EMBEDDING PROCEDURE, THE SPEEDUP OBTAINED BY GT 540M IS BETWEEN 7X AND 26X, AND THE SPEEDUP OBTAINED BY GTX 580 IS BETWEEN 46X AND 73X, FOR VARIOUS CASE STUDIES. FURTHERMORE, IN CASE OF EXTRACTING PROCEDURE, GT 540M LEADS TO A SPEEDUP BETWEEN 10X AND 29X, AND GTX 580 LEADS TO A SPEEDUP BETWEEN 75X AND 80X, FOR VARIOUS CASE STUDIES.