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POOptimized float Blur variations
 

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  1. POOptimized float Blur variations
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    <p>I am looking for optimized functions in c++ for calculating areal averages of floats. the function is passed a source float array, a destination float array (same size as source array), array width and height, "blurring" area width and height.</p> <p>The function should "wrap-around" edges for the blurring/averages calculations.</p> <p>Here is example code that blur with a rectangular shape:</p> <pre><code>/***************************************** * Find averages extended variations *****************************************/ void findaverages_ext(float *floatdata, float *dest_data, int fwidth, int fheight, int scale, int aw, int ah, int weight, int xoff, int yoff) { printf("findaverages_ext scale: %d, width: %d, height: %d, weight: %d \n", scale, aw, ah, weight); float total = 0.0; int spos = scale * fwidth * fheight; int apos; int w = aw; int h = ah; float* f_temp = new float[fwidth * fheight]; // Horizontal for(int y=0;y&lt;fheight ;y++) { Sleep(10); // Do not burn your processor total = 0.0; // Process entire window for first pixel (including wrap-around edge) for (int kx = 0; kx &lt;= w; ++kx) if (kx &gt;= 0 &amp;&amp; kx &lt; fwidth) total += floatdata[y*fwidth + kx]; // Wrap for (int kx = (fwidth-w); kx &lt; fwidth; ++kx) if (kx &gt;= 0 &amp;&amp; kx &lt; fwidth) total += floatdata[y*fwidth + kx]; // Store first window f_temp[y*fwidth] = (total / (w*2+1)); for(int x=1;x&lt;fwidth ;x++) // x width changes with y { // Substract pixel leaving window if (x-w-1 &gt;= 0) total -= floatdata[y*fwidth + x-w-1]; // Add pixel entering window if (x+w &lt; fwidth) total += floatdata[y*fwidth + x+w]; else total += floatdata[y*fwidth + x+w-fwidth]; // Store average apos = y * fwidth + x; f_temp[apos] = (total / (w*2+1)); } } // Vertical for(int x=0;x&lt;fwidth ;x++) { Sleep(10); // Do not burn your processor total = 0.0; // Process entire window for first pixel for (int ky = 0; ky &lt;= h; ++ky) if (ky &gt;= 0 &amp;&amp; ky &lt; fheight) total += f_temp[ky*fwidth + x]; // Wrap for (int ky = fheight-h; ky &lt; fheight; ++ky) if (ky &gt;= 0 &amp;&amp; ky &lt; fheight) total += f_temp[ky*fwidth + x]; // Store first if not out of bounds dest_data[spos + x] = (total / (h*2+1)); for(int y=1;y&lt; fheight ;y++) // y width changes with x { // Substract pixel leaving window if (y-h-1 &gt;= 0) total -= f_temp[(y-h-1)*fwidth + x]; // Add pixel entering window if (y+h &lt; fheight) total += f_temp[(y+h)*fwidth + x]; else total += f_temp[(y+h-fheight)*fwidth + x]; // Store average apos = y * fwidth + x; dest_data[spos+apos] = (total / (h*2+1)); } } delete f_temp; } </code></pre> <p>What I need is similar functions that for each pixel finds the average (blur) of pixels from shapes different than rectangular.</p> <p>The specific shapes are: "S" (sharp edges), "O" (rectangular but hollow), "+" and "X", where the average float is stored at the center pixel on destination data array. Size of blur shape should be variable, width and height.</p> <p>The functions does not need to be pixelperfect, only optimized for performance. There could be separate functions for each shape.</p> <p>I am also happy if anyone can tip me of how to optimize the example function above for rectangluar blurring. </p>
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