Image Steganography is a technique for securing the secret messageusing a cover image in such a manner that the alterations made to the image are perceptually indiscernible. In this paper a novel method for secret messagehiding in color images is proposed. Themessage is encoded by extracting the RGB components of a color image. Run length encoding is performed on the data and insertion of the data in least significiant bits(LSB) of the pixel is guided by linear congruential generator (LCG). A 3R-3G-2B LSB pattern is recommended for insertion of the data making the information more secure without bringing any significant distortions to the original image. The experiments performed on various color images demonstrate the efficacy of the proposed algorithm in terms of PSNR of cover image and that of stego-image.
Image enhancement in digital image processing is one of the main issues. The main purpose of image enhancement is to obtain a high quality image after improving the characteristics of the input image so that output image is better than the original one. Often images obtained from medical imaging systems are of low quality. This may be due to the under-utilization of available range of gray levels. Thus obtained images may suffer from the problems of underexposure and overexposure. In this paper, a new algorithm has been proposed to enhance the medical images. This paper includes the introduction of image enhancement, an overview of different techniques of image enhancement and the new proposed algorithm for image enhancement of medical images. A comparison of existing image enhancement techniques with the proposed techniques based on different performance measures is presented. Experimental results demonstrate that the proposed technique outperforms various existing techniques.
The design of waveforms play an important role in the performance of radar systems. Multicarrier complementary phase-coded signal has been a field of interest for many researchers due to its prominent properties. This paper aims to reduce the Peak-to-Mean Envelope Power Ratio (PMEPR) of a Multicarrier Complementary Phase-Coded (MCPC) signal consisting of P subcarriers which are phase modulated by P phase sequences. The carriers are equally separated in terms of frequency. The carrier separation is equal to the reciprocal of tc, which is equal to the span of each phase element, forming Orthogonal Frequency Division Multiplexing (OFDM). In this paper we propose a new approach to generate MCPC signal using Complementary Block Coding (CBC) method which has lower value of PMEPR in comparison with the conventional method.
This paper describes the Light Field Camera setup, calibration and Raw Light Field Image Processing flow. Plenoptic Camera design has special kind of optical setup, where MLA is placed in between the Main Lens and the Photo Detector, which captures all the light rays entering the Main Lens and generate Raw Light Field Image. Centre detection of macro pixel from the micro lens array is extracted using the algorithm shown in this paper. The post image processing algorithm required to generate extended focus image, perspective view sub-image and epipolar image from raw light field. This paper describes calibration steps involved for customized development for plenoptic camera and post processing algorithm for generation of output images.
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