diff options
| -rw-r--r-- | stripeeraser.m | 25 |
1 files changed, 12 insertions, 13 deletions
diff --git a/stripeeraser.m b/stripeeraser.m index 3198b1f..c0d48a6 100644 --- a/stripeeraser.m +++ b/stripeeraser.m @@ -1,4 +1,4 @@ -function [img_cleaned,img_fourier]=stripeeraser(img,radius,threshold_power) +function [img_cleaned,img_fourier,img_mask]=stripeeraser(img,radius,threshold_power) % Cleans an image from the stripes produced by interference fringes. % Such parallel fringes appears like a strong peak in the Fourier transformed image. % so it easy to clean them, especially if their spatial frequency is high. @@ -11,16 +11,15 @@ img_fourier=fftshift(fft2(img)); % move to Fourier space max1=max(abs(img_fourier(:))); threshold=max1*(10^(-threshold_power)); [Ny, Nx] = size (img); % image size -for x=1:Nx - for y=1:Ny - d=sqrt((x-Nx/2)^2+(y-Ny/2)^2); - if d>radius && abs(img_fourier(y,x))>threshold - % For high enough frequency components - % suppress this frequency components which are mostly stripes. - % But leave untouched small sharp features of the beam - % since they are spectrally weak - img_fourier(y,x)=img_fourier(y,x)*exp(-(d/radius)^2); - end; - end; -end; +[x,y]=meshgrid(1:Nx,1:Ny); % matrix xy coordinates + +d=sqrt((x-(Nx+1)/2).^2+(y-(Ny+1)/2).^2); % distance from center of the image +% For high enough frequency components +% suppress this frequency components which are mostly stripes. +% But leave untouched small sharp features of the beam +% since they are spectrally weak +img_mask = d>radius & abs(img_fourier)>threshold; + +img_fourier(img_mask)=img_fourier(img_mask).*exp(-(d(img_mask)/radius).^2); + img_cleaned = abs( ifft2(ifftshift(img_fourier)) ); |