Bitmap工具类

对Bitmap的一些操作，包括旋转、压缩、截屏、保存等等。

public final class BitmapOperator {public static byte[] convertBitmap2GrayArray(Bitmap img) {byte[] theBytes = null;/* 得到位图的宽高 */int width = img.getWidth();int height = img.getHeight();/* 取得位图的像素点 */int[] pixels = new int[width * height];img.getPixels(pixels, 0, width, 0, 0, width, height);/* 定义结果数据数组 */theBytes = new byte[width * height / 2];/* 定义循环中用到的变量，节约内存和时间 */int x, y, k;int pixel, r, g, b;for (y = 0; y < height; y++) {for (x = 0, k = 0; x < width; x++) {// 依次取得像素点pixel = pixels[y * width + x];// 得到rgbr = (pixel >> 16) & 0xFF;g = (pixel >> 8) & 0xFF;b = pixel & 0xFF;/* 每两行存为一行 */if (x % 2 == 1) {theBytes[k + y * width / 2] = (byte) (theBytes[k + y* width / 2] | ((r * 299 + g * 587 + b * 114 + 500) / 1000) & 0xf0);k++;} else {theBytes[k + y * width / 2] = (byte) (theBytes[k + y* width / 2] | (((r * 299 + g * 587 + b * 114 + 500) / 1000) >> 4) & 0x0f);}}}if (img != null && !img.isRecycled()) {img.recycle();}return theBytes;}/** * 旋转图片 *  * @param bmp * @param degrees * @return */public static Bitmap rotateBitmap(Bitmap bmp, float degrees) {Bitmap bitmap = null;try {Matrix matrix = new Matrix();matrix.setRotate(degrees);bitmap = Bitmap.createBitmap(bmp, 0, 0, bmp.getWidth(),bmp.getHeight(), matrix, true);} catch (Exception e) {e.printStackTrace();}return bitmap;}/* 压缩到指定宽高 */public static Bitmap getBitmapFromFile(String pathName, int width,int height) {BitmapFactory.Options opts = new BitmapFactory.Options();opts.inJustDecodeBounds = true;Bitmap src = BitmapFactory.decodeFile(pathName, opts);opts.outWidth = width;opts.outHeight = height;opts.inJustDecodeBounds = false;src = BitmapFactory.decodeFile(pathName, opts);int w = src.getWidth();int h = src.getHeight();float scaleWidth = ((float) width) / w;float scaleHeight = ((float) height) / h;Matrix matrix = new Matrix();matrix.postScale(scaleWidth, scaleHeight);Bitmap bmp = Bitmap.createBitmap(src, 0, 0, w, h, matrix, true);return bmp;}/** * 保存图片灰度数据到文件 *  * @param path *//* * private void saveImageBytesFile(String path) { Bitmap bmp = * getBitmapFromFile(path, 480, 800); Bitmap img = rotateBitmap(bmp, -90); *  * byte[] buffer = jni_convertIMG2GreyArray(img); if (buffer == null || * buffer.length <= 0) { return; } int length = buffer.length; byte[] data = * new byte[length / 2]; for (int i = 0; i < length / 2; i++) { data[i] = * (byte) ((buffer[i * 2] << 4) & 0xf0 + (buffer[i * 2 + 1] & 0x0f)); } *  * byte[] buffer = convertBitmap2GrayArray(img); if (buffer == null || * buffer.length <= 0) { return; } FileOutputStream fos = null; try { File * file = getFile(); fos = new FileOutputStream(file, false); * fos.write(buffer); fos.flush(); } catch (FileNotFoundException e) { // * TODO Auto-generated catch block e.printStackTrace(); } catch (IOException * e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { * try { if (fos != null) fos.close(); } catch (IOException e) { // TODO * Auto-generated catch block e.printStackTrace(); } } } *//** * 得到文件路径 *  * @return */private File getFile() {File file = new File("/sdcard/EpdiMedia/screen.txt");try {boolean sdCardExist = Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED);if (sdCardExist) {String fileName = "E";String sdPath = Environment.getExternalStorageDirectory().getPath();File tempFile = new File(sdPath + File.separator + fileName);if (!tempFile.exists()) {tempFile.mkdirs();}file = new File(sdPath + File.separator + fileName+ File.separator + "s" + ".txt");/* * if (file.exists()) { file.delete(); file.createNewFile(); } */}} catch (Exception e) {e.printStackTrace();}return file;}/** * 截屏操作 把View转换成Bitmap并保存为文件 文件夹：gh文件名：以时间秒数命名 后缀名：.png *  * @param view */public static void screenShot(View view) {view.setDrawingCacheEnabled(true);view.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED),MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());view.buildDrawingCache();Bitmap bmp = view.getDrawingCache();FileOutputStream fos = null;try {boolean sdCardExist = Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED);if (sdCardExist) {String fileName = "gh";String sdPath = Environment.getExternalStorageDirectory().getPath();File tempFile = new File(sdPath + File.separator + fileName);if (!tempFile.exists()) {tempFile.mkdirs();}File file = new File(sdPath + File.separator + fileName+ File.separator + System.currentTimeMillis() + ".png");if (file.exists()) {file.delete();file.createNewFile();}fos = new FileOutputStream(file);if (fos != null) {bmp.compress(Bitmap.CompressFormat.PNG, 90, fos);fos.close();}}} catch (Exception e) {// Log.e(TAG, "cause for " + e.getMessage());}}}