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copied!<p>In case the image is yuv420 planar, this is how the image data is encoded. Planar meaning the y section is first, followed by U section and then with V section.</p> <p>Considering the width of the image w, and height of the image h.</p> <ol> <li><p>The total size of the image is w*h*3/2</p></li> <li><p>The Y section also called luminescence occupies w*h.</p></li> <li><p>there is a U pixel and V pixel for every 2x2 block in Y section.</p></li> <li><p>the U section comes next, occupies (w/2)*(h/2) and is laid at an offset w*h from beginning of the image.</p></li> <li><p>the V section follows, occupies (w/2)*(h/2) and is laid at an offset of (w*h)+((w*h)/4).</p></li> </ol> <p>In order to rotate the image by 90 degrees, you essentially copy this w*h array to an array of h*w</p> <p>As mentioned in above post, you simply need to copy each of the 3 above Y, U, V blocks separately.</p> <ol> <li><p>Start with the Y section. The 1st pixel to be copied is at (h-1)*w in Source Array, copy this to (0,0) of destination array. The 2nd pixel is at (h-2)*w and so on...</p></li> <li><p>Remember that the U and V sections are only (w/2)*(h/2)</p></li> <li><p>Next copy the U section. The first pixel to be copied is at (w*h)+(((h/2)-1)*(w/2)) in Source Array, copy this to (h*w)+(0,0) in the Destination Array. The 2nd pixel is at (w*h)+(((h/2)-2)*(w/2)) and so on...</p></li> <li><p>Finally copy the V section. The first pixel to be copied is at ((w*h)+(w*h/4))+(((h/2)-1)*(w/2)) in Source Array, copy this to (h*w)+(w*h/4)+(0,0) in the Destination Array. The 2nd pixel is at ((w*h)+(w*h/4))+(((h/2)-2)*(w/2)) and so on...</p></li> </ol> <p>The Destination Array obtained in this way contains the 90 degree rotated image.</p>

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