MATLAB: How to prevent conv2d from changing image size

conv2convolutiondigital image processingimage processingMATLAB

I have an image of size 330×363 uint8. I am convoluting it with 11×11 filter using conv2. The resulting image gets padded with zeros from top (6 pixels), bottom (4 pixels), left (6 pixels), right (4 pixels). Is there a way to prevent this padding from happening? Is it a good practice to crop the resulting image after the convolution?

Best Answer

conv2(A, B, 'same') or conv2(A, B, 'valid')

Related Solutions

MATLAB: Conv vs conv2

The simple difference is that conv() operates on a 1D vector, while conv2() operates on a 2D matrix.

conv() is usually used in the study of linear system analysis and control theory. The most common application of conv() is to find the response of an LTI system. If the impulse response of an LTI system is given, then finding its response to any input is just a matter of finding the convolution of input and impulse response. See these links for more information.

https://en.wikipedia.org/wiki/Linear_time-invariant_system#Impulse_response_and_convolution_2

https://en.wikipedia.org/wiki/Linear_time-invariant_system#Impulse_response_and_convolution

conv2() is mostly used in image processing. It can do a lot of things with images, e.g., blurring, smoothing, sharpening, etc. It is impossible to summarize its application in a single post. Following links will be helpful

https://en.wikipedia.org/wiki/Kernel_(image_processing)

http://www.songho.ca/dsp/convolution/convolution2d_example.html

http://web.pdx.edu/~jduh/courses/Archive/geog481w07/Students/Ludwig_ImageConvolution.pdf