Image Enhancement is the process of escalating the details of an image. We can use image enhancement techniques to improve the quality and the amount of information generated by our image. We can use various gray level transformations such as Linear transfromations, Logarithmic transformation or Power-law transformations.
Negative Transformation is a form of linear transformation which inverts the pixel values i.e. white pixels are converted to black pixels and black pixels are converted to white pixels. Negative Transformation of an image is used to enhance the white or gray detail embedded in dar regions of an image. The negative of an image is given by the expression
\(S = L - 1 - r\)
where L is the maximum pixel intensity possible in the color space, r is the current pixel value and S is the new pixel value.