Image data require huge amounts of disk space and large bandwidths for transmission. Hence, imagecompression is necessary to reduce the amount of data required to represent a digital image. Thereforean efficient technique for image compression is highly pushed to demand. Although, lots of compressiontechniques are available, but the technique which is faster, memory efficient and simple, surely...

The elements of the concrete structure are most frequently affected by cracking. Crack detection is essential to ensure safety and performance during its service life. Cracks do not have a regular shape, in order to achieve the exact dimensions of the crack; the general mathematical formulae are by no means applicable. The authors have proposed a new method which aims to measure the crack dimen...

digital radiographs need additional metadata in order to be accurate when being converted to analog media. resolution is a major reason of failures in proper printing or digitizing the images. this letter shortly explains the overlooked pitfalls of digital radiography and photography in dental practice, and briefly instructs the reader how to avoid or rectify common problems associated with res...

in this paper a wavelet-based logo watermarking scheme is presented. the logo watermark is embedded into all sub-blocks of the lln sub-band of the transformed host image, using quantization technique. extracted logos from all sub-blocks are merged to make the extracted watermark from distorted watermarked image. knowing the quantization step-size, dimensions of logo and the level of wavelet tra...

In this paper a wavelet-based logo watermarking scheme is presented. The logo watermark is embedded into all sub-blocks of the LLn sub-band of the transformed host image, using quantization technique. Extracted logos from all sub-blocks are merged to make the extracted watermark from distorted watermarked image. Knowing the quantization step-size, dimensions of logo and the level of wavelet tra...

This paper presents a modified digital image watermarking method based on nonnegative matrix factorization. Firstly, host image is factorized to the product of three nonnegative matrices. Then, the centric matrix is transferred to discrete cosine transform domain. Watermark is embedded in low frequency band of this matrix and next, the reverse of the transform is computed. Finally, watermarked ...

An optimized method for data hiding into a digital color image in spatial domainis provided. The graph coloring theory with different color numbers is applied. To enhance thesecurity of this method, block correlations method in an image is used. Experimental results showthat with the same PSNR, the capacity is improved by %8, and also security has increased in themethod compared with other meth...