Local and Global Contrast Stretching For Color Contrast Enhancement on Ziehl-Neelsen Tissue Section Slide Images

The enhancement techniques are employed in order to increase the contrast of an image. Generally, an image can be enhanced by spreading out the range of scene illumination. This procedure is called contrast stretching. Contrast stretching (often called normalization) is a simple image enhancement technique that attempts to improve the contrast in an image by ‘stretching’ the range of intensity values it contains to span a desired range of values, the full range of pixel values that the image type concerned allows. Contrast stretching changes the distribution and range of the digital numbers assigned to each pixel in an image. This is normally done to accent image details that may be difficult for the human viewer to observe. Our main goal in this paper is to apply a contrast enhancement technique to recover an image from blurred images, also improve image quality of it. Our technique consists of two steps, locally contrast stretching step and globally contrast stretching step to enhance Ziehl-Neelsen tissue section slide images.