Image hashing allows compression, enhancement or other signal processing operations on digital images which are usually acceptable manipulations. Whereas, cryptographic hash functions are very sensitive to even single bit changes in image. Image hashing is a sum of important quality features in quantized form. In this paper, we proposed a novel image hashing algorithm for authentication which i...

The principle of image enhancement is to improve the interpretability of information contained in the image for human perception or to provide a more suitable input for automated image processing systems. Many images like medical images, satellite images, aerial images and natural images suffer from contrast and noise issues. It is necessary to enhance the contrast and remove the noise to incre...

one of the most common positioning errors in panoramic radiography is palatoglossal air space above the apices of the root of maxillary teeth. it causes a radiolucency obscuring the apices of maxillary teeth. in the case of this positioning error, the imaging should be repeated. this causes the patient be exposed to radiation again. to avoid the repetition of exposing harmful x-rays to the pati...

ÐUnsupervised segmentation of images with low depth of field (DOF) is highly useful in various applications including image enhancement for digital cameras, target recognition, image indexing for content-based retrieval, and 3D microscopic image analysis. This paper describes a novel multiresolution image segmentation algorithm for low DOF images. The algorithm is designed to separate a sharply...

Image fusion is a method for obtaining a highly informative image by merging the relative information of an object obtained from two or more image sources of the same scene. The satellite cameras give a single band panchromatic (PAN) image with high spatial information and multispectral (MS) image with more spectral information. The problem exists today is either PAN or MS image is available fr...

Background: Electronic portal imaging devices (EPIDs) play an important role in radiation therapy portal imaging, geometric and dosimetric verifications. A successful utilization of EPIDs for imaging and dosimetric purposes requires a reliable quality control process routine to be carried out regularly. In this study, two in-house phantoms were developed and analyzed for implementation in a qua...

Multiresolution histograms have been used for indexing and retrieval of images. Multiresolution histograms used traditionally are 2d-histograms which encode pixel intensities. Earlier we proposed a method for decomposing images by connectivity. In this paper, we propose to encode centroidal distances of an image in multiresolution histograms; the image is decomposed a priori, by connectivity. M...

Image enhancement is very important in the field where visual appearance of an image is the main. Image enhancement is the process of improving the image in such a way that the resulting or output image is more suitable than the original image for specific task. With the help of image enhancement process the quality of image can be improved to get good quality images so that they can be clear f...

abtract background: in nuclear medicine, phantoms are mainly used to evaluate the overall performance of the imaging systems and practically there is no phantom exclusively designed for the evaluation of the software performance.  in this study the hoffman brain phantom was used for quantitative evaluation of reconstruction techniques. the phantom is modified to acquire tomographic and planar i...