Legacy ImageMagick Discussions Archive

Hi..

My aim is to extract the phase information in images,but i dont have idea about the phase information.

I searched many documents to understand the phase information,but they are very complicated to understand.

please any one explain or give any URL for understanding of phase information in image.

convert image -fft result_%d.png

result_0.png is the magnitude image that needs to be processed by -evaluate log 100000 to see anything.

result_1.png is the phase image


see
http://www.fmwconcepts.com/imagemagick/ ... urier.html

Thanks for your reply....

I choose gabor filter for extracting phase information,but i dont know whether gabor filter is applied in spatial domain or frequency domain.

please guide me how can i use gabor filter...

Sorry I do not know anything about the Gabor filter. Do you have a reference?

According to http://mplab.ucsd.edu/tutorials/gabor.pdf and http://en.wikipedia.org/wiki/Gabor_filter, the gabor filter can be constructed in either the spatial or frequency domains. In the spatial domain, it is the product of a Gaussian function with a complex sinusoid function. It is a windowed (by the Gaussian) complex sinusoid. Thus it is a tapered complex sinusoid.

Its use is to identify regions of a given frequency and orientation. One application is to segment an image of various texture patterns. See http://www.cse.iitm.ac.in/~sdas/vplab/c ... r_filt.pdf. Imagemagick does not currently have a Gabor filter function.

Applications usually ignore the phase and look more to the magnitude to get a measure of energy.