Application of Niblack's method on images

Image segmentation is a major step in image analysis and processing. Segmentation is performed through several methods. In this work Niblack's method of segmentation is further studied. It is one of the local thresholding techniques for segmentation. The output of Niblack's method is significant and has most acceptable result out of all thresholding techniques in segmenting text documents. In this work the same method is applied on images keeping one of the variables i.e. weight k of Niblack's method constant while changing the other (window size) from images to images. The output image is better segmented but the background is noisy. Improvements in the resultant images are demonstrated by applying the morphological operations of opening and closing. Opening and closing are combination of two fundamental morphological operations dilation and erosion. Dilation thickens objects in a binary image by adding pixels to the boundaries of the objects, while erosion shrinks objects in a binary image.