The exact positioning of patients during radiotherapy is essential for high precision treatment. The registration of portal image sequences (megavoltage X-ray images) can help to control the patient position. The particular problem of portal imaging devices is that they provide imagery with extremely low contrast. Therefore, feature extraction followed by binary feature matching is a difficult ...

Image enhancement is one of the challenging issues in low level image processing. Contrast enhancement techniques are used for improving visual quality of low contrast images. Histogram Equalization (HE) method is one such technique used for contrast enhancement. It is a contrast enhancement technique with the objective to obtain a new enhanced image with a uniform histogram. In this paper, ins...

Enhancement is one of the challenging factors in image processing. The objective of enhancement is to improve the structural appearance of an image without any degradation in the input image. The enhancement techniques make the identification of key features easier by removing noise and other artifacts in an image. This paper analyzes the performance of various enhancement techniques based on n...

The main purpose of image enhancement is to bring out detail that is hidden in an image or to increase contrast in a low contrast image. Image enhancement techniques provide a multitude of choices for improving the visual quality of images. Appropriate choice of such techniques is greatly influenced by the imaging modality, task at hand and viewing conditions. This paper analyses the performanc...

Satellite image is used in many applications such as geosciences studies, astronomy and geographical information systems. The most important quality factors in images come from its resolution. The satellite image enhancement technique using Discrete Wavelet Transform and Singular Value Decomposition. This Techniques decomposes the input image into four frequency sub band by using Discrete Wavel...

The energy compaction and multiresolution properties of wavelets have made the image fusion successful in combining important features such as edges and textures from source images without introducing any artifacts for context enhancement and situational awareness. The wavelet transform is visualized as a convolution of wavelet filter coefficients with the image under consideration and is compu...

In medical image processing, retinal image enhancement is the challenging issue to reveal the unseen details of an retinal image, thus, in many applications image enhancement issued to solve the challenges such as, noise reduction, blurring, degradation, etc. To improve the visual grade of retinal images we have many alternative image enhancement techniques that are suitable for specific applic...

There are a lot of images around carrying valuable information yet because of its poor quality, necessary information cannot be extracted. A low quality image is perceived to have low contrast and poorly defined boundaries between the edges. Most watched images speak to just a corrupted form of the first scene since genuine imaging systems and additionally imaging conditions are normally poor. ...

We solve the problem of quantitative measuring of image quality, beyond the widely used MSE (mean square error) or even visual comparison. We combine eight feature-based and perceptually-oriented image quality metrics. The need for this comes from virtual archaeology, where various image acquisitions, antialiasing, multiresolution, image reconstruction or texturing methods produce very similar ...