This paper proposes an improved dark channel prior for removing haze from images. Dark channel prior is an effective method for removing haze. Dark channel is an image in the same size as the hazy image which is obtained by dividing the RGB images into windows and for each window, the minimum of each R, G and B channels are calculated. Then again the minimum of these three values is calculated ...

introduction: filtering can greatly affect the quality of clinical images. determining the best filter and the proper degree of smoothing can help to ensure the most accurate diagnosis. methods: forty five patient’s data aquired during brain phantom spect studies were reconstructed using filtered back-projection technique. the ramp, shepp-logan, cosine, hamming, hanning, butterworth, metz and w...

Enhancing image quality has become an important issue as the volume of digital images increases exponentially and the expectation of high-quality images grows insatiably. Digitized images commonly suffer from poor visual quality due to distortions, low contrast, the deficiency of lighting, defocusing, atmospheric influences such as fog, severe compression, and transmission errors. Hence, image ...

Image fusion and denoising have been widely researched as separate techniques for the past few decades. Most of the fusion techniques fuse the images with the assumption that images are nonnoisy. But in many practical applications, especially, in the case of satellite images this assumption fails. In this paper, a novel technique based on nonlocal means filter in conjunction with multiresolutio...

The Electronic Portal Imaging Device has become an important tool for the clinician to verify the shape and the location of the therapy beam with respect to the patient’s anatomy [13]. Electronic Portal Imaging Devices use the high-energy treatment beam to project the body interior of the patient onto a fluorescent screen that is scanned by a camera. After on-line digitization, the images are a...

Image Enhancement is one of the most important and difficult techniques in image research. The aim of image enhancement is to improve the visual appearance of an image, or to provide a “better transform representation for future automated image processing. Many images like medical images, satellite images, aerial images and even real life photographs suffer from poor contrast and noise. It is n...

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...

The megavoltage electronic portal imaging is a very important task for cancer treatment in the radiation therapy. The megavoltage images (MVIs) , however, are very poor in quality because of imaging physics. For a reliable patient set-up verification we need better in-treatment images to track relevant features. In recent years, some researchers have applied the concept of fuzzy set theory to d...

This study presents a method to reconstruct a high-resolution image using a deep convolution neural network. We propose a deep model, entitled Deep Block Super Resolution (DBSR), by fusing the output features of a deep convolutional network and a shallow convolutional network. In this way, our model benefits from high frequency and low frequency features extracted from deep and shallow networks...

The aim of image enhancement is to improve the perception of information in images for human viewers, or to provide better input for other automated image processing images. Image Enhancement (IE) transforms images to provide better representation of subtle details. Contrast stretching is an image enhancement technique commonly used for medical images for improving the quality of an image by re...