Matlab – Spatial Filtering

Filtering is a technique for modifying or enhancing an image. As it name stated, spatial filtering use filter or also know as mask, kernel, template or window. Values of filter sub image are referred to coefficients rather than pixel intensities. Masks are always in odd size such as 3×3, 3×5 or etc. You won’t be able to find the center of the mask if it’s in even size. The process is simply moving the filter mask from point to point in an image. The filter oat each point is calculated using predefined relationship. Continue reading “Matlab – Spatial Filtering”

Matlab – Point Functions and Histogram Image Segmentation

In image processing point operation or function results in new histogram different from the original image. It is basically taking average of several points and make it into one points such as b(i,j) = 10 round (A(i,j) / 10). You can clearly see the difference in histogram view. Image segmentation somehow related to point functions. A scene in an image composed of several different regions, object and etc. Segmentation is decomposition of an image into these regions or objects. As a human, we can easily identify each of object in an image. However, automatic segmentation using computer algorithm is difficult and right now consider unresolved. Automatic segmentation of image is still actively researched.  Continue reading “Matlab – Point Functions and Histogram Image Segmentation”

Matlab – Dilation and Erosion

In digital image processing, you must understand on dilation and erosion. Dilation adds pixels to the boundaries of objects in an image. On the other hand erosion removes pixels on object boundaries. The number of pixels added or removed from the objects in an
image depends on the size and shape of the structuring element used to process the image. In the morphological dilation and erosion operations, the state of any given pixel in the output image is determined by applying a rule to the corresponding pixel and its neighbors in the input image. The rule used to process the pixels defines the operation
as a dilation or an erosion. Continue reading “Matlab – Dilation and Erosion”