A method for contrast enhancement is proposed. The algorithm is based on a local and image-dependent exponential correction. The technique aims to correct images that simultaneously present overexposed and underexposed regions. To prevent halo artifacts, the bilateral filter is used as the mask of the exponential correction. Depending on the characteristics of the image (piloted by histogram an...

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...

Purposes of Image Contrast Enhancement Enhancements are used to improve the appearance of an image and make it easier for visual interpretation, understanding, and analysis of imagery. There are a variety of point and local image enhancement operations. Point operations modify the DN of each pixel in an image independently, such as contrast stretching; Local operations modify the value of each ...

Given two images of the same scene taken at diierent times or with diierent cameras, we propose an "image intersection" method. Contrast invariant image intersection permits to generate a new image which does not depend upon the contrast of the cameras or the overall diierences in illumination of the scene at diierent times. We call section of a digital image u(x) any connected component of a b...