Transforming a square image to an image of curved sides

Question

Luis 2012-3-16

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/32494-transforming-a-square-image-to-an-image-of-curved-sides

采纳的回答： Sean de Wolski

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Hi all!

I'd be very thankful for any tip on this!

Challenge:

I have a square picture of the moon (1024x1024 pixels). The 4 corners all have different coordinates (latitude and longitude). I have interpolated the coordinates for the image every 8 pixels and I can creat a matrix with that info.

My solution:

I though of interpolating all the coordinates for all the pixels and then put the pixel in the coordinate matrix but that takes me an hour to compute an image... and I have several hundred thousands to process.

Question:

Is there any other method to transform a square image into another image with non linear sides?

Thank you all!

The code here:

     for x=1:129
        for y=1:121
                inputPointsX(y,x)=(coords{(x-1)*121+y,4}-mapCoord(4,2))*xScale;
                inputPointsY(y,x)=(coords{(x-1)*121+y,3}-mapCoord(4,1))*yScale;
        end
     end
    xcoords = 1:129;
    ycoords = 1:121; 
    [X,Y] = meshgrid(xcoords,ycoords);   
    try 
    for x=1:1024      % Interpolated version - SLOW!!!
         for y=1:1024-64
             xccc = interp2(X,Y,inputPointsX,x/8+1,y/8+1);
             yccc = interp2(X,Y,inputPointsY,x/8+1,y/8+1);
             Image(round(yccc),round(xccc))=I(y,x);
         end
    end