package com.jwetherell.motiondetection.image; import java.io.ByteArrayOutputStream; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Color; import android.graphics.Matrix; /** * This abstract class is used to process images. * * @author Justin Wetherell <[email protected]> */ public abstract class ImageProcessing { public static final int A = 0; public static final int R = 1; public static final int G = 2; public static final int B = 3; public static final int H = 0; public static final int S = 1; public static final int L = 2; private ImageProcessing() { } /** * Get RGB values from pixel. * * @param pixel * Integer representation of a pixel. * @return float array of a,r,g,b values. */ public static float[] getARGB(int pixel) { int a = (pixel >> 24) & 0xff; int r = (pixel >> 16) & 0xff; int g = (pixel >> 8) & 0xff; int b = (pixel) & 0xff; return (new float[] { a, r, g, b }); } /** * Get HSL (Hue, Saturation, Luma) from RGB. Note1: H is 0-360 (degrees) * Note2: S and L are 0-100 (percent) * * @param r * Red value. * @param g * Green value. * @param b * Blue value. * @return Integer array representing an HSL pixel. */ public static int[] convertToHSL(int r, int g, int b) { float red = r / 255; float green = g / 255; float blue = b / 255; float minComponent = Math.min(red, Math.min(green, blue)); float maxComponent = Math.max(red, Math.max(green, blue)); float range = maxComponent - minComponent; float h = 0, s = 0, l = 0; l = (maxComponent + minComponent) / 2; if (range == 0) { // Monochrome image h = s = 0; } else { s = (l > 0.5) ? range / (2 - range) : range / (maxComponent + minComponent); if (red == maxComponent) { h = (blue - green) / range; } else if (green == maxComponent) { h = 2 + (blue - red) / range; } else if (blue == maxComponent) { h = 4 + (red - green) / range; } } // convert to 0-360 (degrees) h *= 60; if (h < 0) h += 360; // convert to 0-100 (percent) s *= 100; l *= 100; // Since they were converted from float to int return (new int[] { (int) h, (int) s, (int) l }); } /** * Decode a YUV420SP image to Luma. * * @param yuv420sp * Byte array representing a YUV420SP image. * @param width * Width of the image. * @param height * Height of the image. * @return Integer array representing the Luma image. * @throws NullPointerException * if yuv420sp byte array is NULL. */ public static int[] decodeYUV420SPtoLuma(byte[] yuv420sp, int width, int height) { if (yuv420sp == null) throw new NullPointerException(); final int frameSize = width * height; int[] hsl = new int[frameSize]; for (int j = 0, yp = 0; j < height; j++) { for (int i = 0; i < width; i++, yp++) { int y = (0xff & (yuv420sp[yp])) - 16; if (y < 0) y = 0; hsl[yp] = y; } } return hsl; } /** * Decode a YUV420SP image to RGB. * * @param yuv420sp * Byte array representing a YUV420SP image. * @param width * Width of the image. * @param height * Height of the image. * @return Integer array representing the RGB image. * @throws NullPointerException * if yuv420sp byte array is NULL. */ public static int[] decodeYUV420SPtoRGB(byte[] yuv420sp, int width, int height) { if (yuv420sp == null) throw new NullPointerException(); final int frameSize = width * height; int[] rgb = new int[frameSize]; for (int j = 0, yp = 0; j < height; j++) { int uvp = frameSize + (j >> 1) * width, u = 0, v = 0; for (int i = 0; i < width; i++, yp++) { int y = (0xff & (yuv420sp[yp])) - 16; if (y < 0) y = 0; if ((i & 1) == 0) { v = (0xff & yuv420sp[uvp++]) - 128; u = (0xff & yuv420sp[uvp++]) - 128; } int y1192 = 1192 * y; int r = (y1192 + 1634 * v); int g = (y1192 - 833 * v - 400 * u); int b = (y1192 + 2066 * u); if (r < 0) r = 0; else if (r > 262143) r = 262143; if (g < 0) g = 0; else if (g > 262143) g = 262143; if (b < 0) b = 0; else if (b > 262143) b = 262143; rgb[yp] = 0xff000000 | ((r << 6) & 0xff0000) | ((g >> 2) & 0xff00) | ((b >> 10) & 0xff); } } return rgb; } /** * Convert an RGB image into a Bitmap. * * @param rgb * Integer array representing an RGB image. * @param width * Width of the image. * @param height * Height of the image. * @return Bitmap of the RGB image. * @throws NullPointerException * if RGB integer array is NULL. */ public static Bitmap rgbToBitmap(int[] rgb, int width, int height) { if (rgb == null) throw new NullPointerException(); Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565); bitmap.setPixels(rgb, 0, width, 0, 0, width, height); return bitmap; } /** * Convert an Luma image into Greyscale. * * @param lum * Integer array representing an Luma image. * @param width * Width of the image. * @param height * Height of the image. * @return Bitmap of the Luma image. * @throws NullPointerException * if RGB integer array is NULL. */ public static Bitmap lumaToGreyscale(int[] lum, int width, int height) { if (lum == null) throw new NullPointerException(); Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565); for (int y = 0, xy = 0; y < bitmap.getHeight(); y++) { for (int x = 0; x < bitmap.getWidth(); x++, xy++) { int luma = lum[xy]; bitmap.setPixel(x, y, Color.argb(1, luma, luma, luma)); } } return bitmap; } /** * Rotate the given Bitmap by the given degrees. * * @param bmp * Bitmap to rotate. * @param degrees * Degrees to rotate. * @return Bitmap which was rotated. */ public static Bitmap rotate(Bitmap bmp, int degrees) { if (bmp == null) throw new NullPointerException(); // getting scales of the image int width = bmp.getWidth(); int height = bmp.getHeight(); // Creating a Matrix and rotating it to 90 degrees Matrix matrix = new Matrix(); matrix.postRotate(degrees); // Getting the rotated Bitmap Bitmap rotatedBmp = Bitmap.createBitmap(bmp, 0, 0, width, height, matrix, true); ByteArrayOutputStream stream = new ByteArrayOutputStream(); rotatedBmp.compress(Bitmap.CompressFormat.JPEG, 100, stream); return rotatedBmp; } /** * Rotate the given image in byte array format by the given degrees. * * @param data * Bitmap to rotate in byte array form. * @param degrees * Degrees to rotate. * @return Byte array format of an image which was rotated. */ public static byte[] rotate(byte[] data, int degrees) { if (data == null) throw new NullPointerException(); // Convert the byte data into a Bitmap Bitmap bmp = BitmapFactory.decodeByteArray(data, 0, data.length); // Getting the rotated Bitmap Bitmap rotatedBmp = rotate(bmp, degrees); // Get the byte array from the Bitmap ByteArrayOutputStream stream = new ByteArrayOutputStream(); rotatedBmp.compress(Bitmap.CompressFormat.JPEG, 100, stream); return stream.toByteArray(); } }