ABSTRACT
Contrast is a measure of the variation in intensity or gray value in a specified region of an image. In all
applications concerning image acquisition, followed by processing of images, successful pre-processing is of the
essence. Every sensor has its own characteristics, but in general the quality of the acquired MR image is fairly
poor. Overall grayscale intensity variations, poor contrast and noisy background are the frequently encountered
issues. The Rational Unsharp Masking method is the one introduced here to improve the quality of the MR image.
It is demonstrated, that the proposed method has much reduced noise sensitivity than another polynomial
operator, Cubic Unsharp masking and number of approaches devised to improve the perceived quality of an
image. This algorithm has been tested for various slices of axial, sagittal and coronal sections of MR image. The
results confirm the ability of the algorithm to produce better quality images, helpful to have effective diagnosis.
Keywords: - Image enhancement, Magnetic Resonance Image , Rational filters, Unsharp Masking.