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POHow to reverse that function
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  1. POHow to reverse that function
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    copied!<p>I've asked before about the opposite of Bitwise AND(&amp;) and you told me its impossible to reverse.</p> <p>Well,this is the situation: The server sends an image,which is encoded with the function I want to reverse,then it is encoded with zlib.</p> <p>This is how I get the image from the server:</p> <pre><code> UInt32[] image = new UInt32[200 * 64]; int imgIndex = 0; byte[] imgdata = new byte[compressed]; byte[] imgdataout = new byte[uncompressed]; Array.Copy(data, 17, imgdata, 0, compressed); imgdataout = zlib.Decompress(imgdata); for (int h = 0; h &lt; height; h++) { for (int w = 0; w &lt; width; w++) { imgIndex = (int)((height - 1 - h) * width + w); image[imgIndex] = 0xFF000000; if (((1 &lt;&lt; (Int32)(0xFF &amp; (w &amp; 0x80000007))) &amp; imgdataout[((h * width + w) &gt;&gt; 3)]) &gt; 0) { image[imgIndex] = 0xFFFFFFFF; } } } </code></pre> <p>Width,Height,Image decompressed and Image compressed length are always the same.</p> <p>When this function is done I put image(UInt32[] array) in a Bitmap and I've got it.</p> <p>Now I want to be the server and send that image.I have to do two things:</p> <p>Reverse that function and then compress it with zlib.</p> <p>How do I reverse that function so I can encode the picture?</p> <pre><code> for (int h = 0; h &lt; height; h++) { for (int w = 0; w &lt; width; w++) { imgIndex = (int)((height - 1 - h) * width + w); image[imgIndex] = 0xFF000000; if (((1 &lt;&lt; (Int32)(0xFF &amp; (w &amp; 0x80000007))) &amp; imgdataout[((h * width + w) &gt;&gt; 3)]) &gt; 0) { image[imgIndex] = 0xFFFFFFFF; } } } </code></pre> <p>EDIT:The format is 32bppRGB</p>
 

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