Steganography is primarily used for the covert transmission of information even though the purpose can be legitimate or malicious. The primary purpose of this work is to build a firewall which will thwart this transmission. This will be achieved by radiometric and geometric operations. These operations will degrade the quality of cover image. However these can be restored to some extent by a deconvolution operation. The finally deconvolved image is subjected to steganalysis to verify the absence of stego content. Experimental results showed that PSNR and SSIM values are between 35 dB -45 dB and 0.96, respectively which are above the acceptable range. Our method can suppress the stego content to large extent irrespective of embedding algorithm in spatial and transform domain. We verified by using RS steganalysis, difference image histogram and chi-square attack, that 95 per cent of the stego content embedded in the spatial domain was removed by our showering techniques. We also verified that 100 per cent of the stego content was removed in the transform domain with PSNR 30 dB -45 dB and SSIM between 0.67-0.99. Percentage of stego removed in both domains was measured by using bit error rate and first order Markov feature.

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Covert transmission of information hidden in different media to either a general or targeted audience constitutes steganography. However, this technique can be misused to transmit undesirable information. Traditionally the removal of such content necessitated the knowledge of the steganographic algorithm used. However, we address the scenario where such stego is removed using generic image processing operations along with an anti forensic method without assuming any knowledge of the steganographic algorithm used. The application of generic image processing operations also causes degradation of cover image, which can also be restored using this anti forensic method. Our procedure has been tested on a variety of steganographic algorithms including HUGO-BD, WOW, Synch and J-UNIWARD. By applying universal steganalysis we found that all images which have been subjected to our procedure have become stego free. However, a direct evaluation of the stego content assuming knowledge of the stego content and its location showed that 80 percentage of the stego is removed without significantly impacting the visual image quality. Video stream containing isolated static images have been addressed in this paper. The peak signal-to-noise ratio and structural

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