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POHow to selectively apply processing algorithm to certain color channel(s) in Java
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copied!<p>I'm developing an image processing library for Android which has ability to apply adjustments to image.</p> <p>At first, I process each bits like this:</p> <pre><code>public int[] getProcessedPixels(int[] pixels) { int a, r, g, b; for(int i = 0; i < pixels.length; i++) { a = Color.alpha(pixels[i]); r = Color.red(pixels[i]); g = Color.green(pixels[i]); b = Color.blue(pixels[i]); a = doSomethingWithThisChannel(a); r = doSomethingWithThisChannel(r); g = doSomethingWithThisChannel(g); b = doSomethingWithThisChannel(b); // Merge back all 4 channels to pixel value pixels[i] = Color.argb(a, r, g, b); } return pixels; } // Usage sample int[] pixels = bitmap.getAllPixels(); // each pixels is hexa 0xAARRGGBB int[] resultPixels = getProcessedPixels(pixels); // it returns result pixels </code></pre> <p>Since I'm developing <strong>a library</strong>, I want to let developers who use it to be able to <strong>apply "doSomethingWithThisChannel" method to any channel(s) as needed</strong></p> <p>I want to change the method like this (it's a copy of the above method, but simplified):</p> <pre><code>public int[] getProcessedPixels(int[] pixels) { // assume process all channels if not specified return getProcessedPixels(pixels, Channel.ALL); } public int[] getProcessedPixels(int[] pixels, int channels) { int a, r, g, b; for(int i = 0; i < pixels.length; i++) { pixels[i] = doSomethingWithTHESEChannels(pixels[i], channels); } return pixels; } // Usage sample int channels = Channel.RED | Channel.GREEN; // ONLY apply processing to RED & GREEN channels int[] pixels = bitmap.getAllPixels(); // each pixels is hexa 0xAARRGGBB int[] resultPixels = getProcessedPixels(pixels, channels); </code></pre> <p>This is my static class to define "bitmasks" (cmiiw) for each ARGB color channel I used in the code above:</p> <pre><code>public class Channel { public static final int NONE = 0x00000000; public static final int ALL = 0xffffffff; public static final int ALPHA = 0xff000000; public static final int RED = 0x00ff0000; public static final int GREEN = 0x0000ff00; public static final int BLUE = 0x000000ff; } </code></pre> <p>Do you have any suggestion how should I implement <code>doSomethingWithTHESEChannels</code> method above? I'm pretty sure it will involve bitmask/bit-manipulation.</p>

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