#For loops matlab how to

Hope you got an idea of how to avoid traditional for loop in spatial coordinates based operation.

#For loops matlab code

Results are same as previous code are below. Img = cast(imresize(imread(file),scale),'double') This is the traditional code I used in my previous article. Following example demonstrate how to use this method for focal BW effect. Now you can perform any coordinate based example as in matrix handling without using for loops. Now wipe unwanted вЂcordвЂ™ matrix from memory. Now fill the coordinate matrix using repmat command as below. Next step is to get the dimensions of the image Say the matrix which contains your image data is вЂimgвЂ™ with the datatype of вЂuint8вЂ™. Using the properties of complex numbers we can easily calculate the distance and angle between two pixels in interest which is very useful in image effects such as вЂfocal BWвЂ™.ДЇirst of all letвЂ™s look how to create this coordinate matrix. This 4 th matrix contains complex numbers which their real value is equal to row index and its imaginary value is equal to its column index. (Even-though there is a memory drawback in this design, it is very easy to handle rather than two nested вЂforвЂ™ loops). In my case I append another 4 th matrix of coordinates which makes the image matrix as mxnx4. Normally in an image there is an mxnx3 matrix which represents red, green and blue intensities respectively. In this article I share my experience how I avoided the requirement of two вЂforвЂ™ loops by using the properties of complex numbers for a photo effect which I described in a previous article of mine. Viewed 429 times 1 I have this function below, but the if statement inside the for loop doesnt work. Ask Question Asked 8 years, 5 months ago. This is very annoying since it takes quite some time to process two вЂforвЂ™ loops as well as it is a belief that the MATLAB вЂforвЂ™ loops are used to slow. IF inside FOR loop in Matlab doesnt work. While working on some image enhancement applications which the intensity of a given pixel is also a function of its location (spatial coordinates), I used to use вЂforвЂ™ loops to iterate each pixel at once and calculate its intensity based on (x,y) value obtained from those two вЂforвЂ™ loops.

Process spatial operations without вЂforвЂ™ loops inВ MATLAB