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copied!<p>If I get you right, then if you have an image like this</p> <pre><code>p00|p01|p02|... ---+---+------- p10|p11|p12|... ---+---+------- p20|p21|p22|... ---+---+---+--- ...|...|...|... </code></pre> <p>Which is stored in an array in left-to-right row scan like this:</p> <pre><code>p00,p01,...,p0n, p10,p11,...,p1n, p20,p21, ... </code></pre> <p>If I understand you correctly, what you want to be able to do, is to take a given rectangle (from a certain x and y with a certain width and height) from the image. Here is code to do this, with explanations:</p> <pre><code>byte[] crop_area (byte[] source_image, int image_width, int image_height, int start_x, int start_y, int result_width, int result_height) { byte[] result = new byte[result_width * result_height]; int endX = x + result_width; int endY = y + result_height; int pos = 0; for (int y = startY; y < endY; y++) for (int x = startX; x < endX; x++) { /* To get to the pixel in the row I (starting from I=1), we need * to skip I-1 rows. Since our y indexes start from row 0 (not 1), * then we don't need to subtract 1. * * So, the offset of the pixel at (x,y) is: * * y * image_width + x * |-----------------------| |-----------------| * Skip pixels of y rows Offset inside row */ result[pos] = source_image[y * image_width + x]; /* Advance to the next pixel in the result image */ pos++; } return result; } </code></pre> <p>Then, to take the block in the row I and column J (I,J=0,...,14) do:</p> <pre><code>crop_area (source_image, image_width, image_height, J*image_width/15, I*image_height/15, image_width/15, image_height/15) </code></pre>

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