Android之多种Bitmap效果
1. 将图片变为圆角
2. 获取缩略图图片
3. LOMO特效
4. 旧时光特效
5. 暖意特效
6. 根据饱和度、色相、亮度调整图片
7. 添加图片外边框
8. 添加内边框
9. 创建一个缩放的图片
/** * 图片工具类 * * @author rendongwei * */ public class PhotoUtil { /** * 将图片变为圆角 * * @param bitmap * 原Bitmap图片 * @param pixels * 图片圆角的弧度(单位:像素(px)) * @return 带有圆角的图片(Bitmap 类型) */ public static Bitmap toRoundCorner(Bitmap bitmap, int pixels) { Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Config.ARGB_8888); Canvas canvas = new Canvas(output); final int color = 0xff424242; final Paint paint = new Paint(); final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight()); final RectF rectF = new RectF(rect); final float roundPx = pixels; paint.setAntiAlias(true); canvas.drawARGB(0, 0, 0, 0); paint.setColor(color); canvas.drawRoundRect(rectF, roundPx, roundPx, paint); paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN)); canvas.drawBitmap(bitmap, rect, rect, paint); return output; } public static boolean saveToSDCard(Bitmap bitmap) { if (!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) { return false; } FileOutputStream fileOutputStream = null; File file = new File("/sdcard/KaiXin/Download/"); if (!file.exists()) { file.mkdirs(); } String fileName = UUID.randomUUID().toString() + ".jpg"; String filePath = "/sdcard/KaiXin/Download/" + fileName; File f = new File(filePath); if (!f.exists()) { try { f.createNewFile(); fileOutputStream = new FileOutputStream(filePath); bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fileOutputStream); } catch (IOException e) { return false; } finally { try { fileOutputStream.flush(); fileOutputStream.close(); } catch (IOException e) { return false; } } } return true; } /** * 保存图片到本地(JPG) * * @param bm * 保存的图片 * @return 图片路径 */ public static String saveToLocal(Bitmap bm) { if (!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) { return null; } FileOutputStream fileOutputStream = null; File file = new File("/sdcard/KaiXin/Images/"); if (!file.exists()) { file.mkdirs(); } String fileName = UUID.randomUUID().toString() + ".jpg"; String filePath = "/sdcard/KaiXin/Images/" + fileName; File f = new File(filePath); if (!f.exists()) { try { f.createNewFile(); fileOutputStream = new FileOutputStream(filePath); bm.compress(Bitmap.CompressFormat.JPEG, 100, fileOutputStream); } catch (IOException e) { return null; } finally { try { fileOutputStream.flush(); fileOutputStream.close(); } catch (IOException e) { return null; } } } return filePath; } /** * 保存图片到本地(PNG) * * @param bm * 保存的图片 * @return 图片路径 */ public static String saveToLocalPNG(Bitmap bm) { if (!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) { return null; } FileOutputStream fileOutputStream = null; File file = new File("/sdcard/KaiXin/Images/"); if (!file.exists()) { file.mkdirs(); } String fileName = UUID.randomUUID().toString() + ".png"; String filePath = "/sdcard/KaiXin/Images/" + fileName; File f = new File(filePath); if (!f.exists()) { try { f.createNewFile(); fileOutputStream = new FileOutputStream(filePath); bm.compress(Bitmap.CompressFormat.PNG, 100, fileOutputStream); } catch (IOException e) { return null; } finally { try { fileOutputStream.flush(); fileOutputStream.close(); } catch (IOException e) { return null; } } } return filePath; } /** * 获取缩略图图片 * * @param imagePath * 图片的路径 * @param width * 图片的宽度 * @param height * 图片的高度 * @return 缩略图图片 */ public static Bitmap getImageThumbnail(String imagePath, int width, int height) { Bitmap bitmap = null; BitmapFactory.Options options = new BitmapFactory.Options(); options.inJustDecodeBounds = true; // 获取这个图片的宽和高，注意此处的bitmap为null bitmap = BitmapFactory.decodeFile(imagePath, options); options.inJustDecodeBounds = false; // 设为 false // 计算缩放比 int h = options.outHeight; int w = options.outWidth; int beWidth = w / width; int beHeight = h / height; int be = 1; if (beWidth < beHeight) { be = beWidth; } else { be = beHeight; } if (be <= 0) { be = 1; } options.inSampleSize = be; // 重新读入图片，读取缩放后的bitmap，注意这次要把options.inJustDecodeBounds 设为 false bitmap = BitmapFactory.decodeFile(imagePath, options); // 利用ThumbnailUtils来创建缩略图，这里要指定要缩放哪个Bitmap对象 bitmap = ThumbnailUtils.extractThumbnail(bitmap, width, height, ThumbnailUtils.OPTIONS_RECYCLE_INPUT); return bitmap; } /** * LOMO特效 * * @param bitmap * 原图片 * @return LOMO特效图片 */ public static Bitmap lomoFilter(Bitmap bitmap) { int width = bitmap.getWidth(); int height = bitmap.getHeight(); int dst[] = new int[width * height]; bitmap.getPixels(dst, 0, width, 0, 0, width, height); int ratio = width > height ? height * 32768 / width : width * 32768 / height; int cx = width >> 1; int cy = height >> 1; int max = cx * cx + cy * cy; int min = (int) (max * (1 - 0.8f)); int diff = max - min; int ri, gi, bi; int dx, dy, distSq, v; int R, G, B; int value; int pos, pixColor; int newR, newG, newB; for (int y = 0; y < height; y++) { for (int x = 0; x < width; x++) { pos = y * width + x; pixColor = dst[pos]; R = Color.red(pixColor); G = Color.green(pixColor); B = Color.blue(pixColor); value = R < 128 ? R : 256 - R; newR = (value * value * value) / 64 / 256; newR = (R < 128 ? newR : 255 - newR); value = G < 128 ? G : 256 - G; newG = (value * value) / 128; newG = (G < 128 ? newG : 255 - newG); newB = B / 2 + 0x25; // ==========边缘黑暗==============// dx = cx - x; dy = cy - y; if (width > height) dx = (dx * ratio) >> 15; else dy = (dy * ratio) >> 15; distSq = dx * dx + dy * dy; if (distSq > min) { v = ((max - distSq) << 8) / diff; v *= v; ri = newR * v >> 16; gi = newG * v >> 16; bi = newB * v >> 16; newR = ri > 255 ? 255 : (ri < 0 ? 0 : ri); newG = gi > 255 ? 255 : (gi < 0 ? 0 : gi); newB = bi > 255 ? 255 : (bi < 0 ? 0 : bi); } // ==========边缘黑暗end==============// dst[pos] = Color.rgb(newR, newG, newB); } } Bitmap acrossFlushBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565); acrossFlushBitmap.setPixels(dst, 0, width, 0, 0, width, height); return acrossFlushBitmap; } /** * 旧时光特效 * * @param bmp * 原图片 * @return 旧时光特效图片 */ public static Bitmap oldTimeFilter(Bitmap bmp) { int width = bmp.getWidth(); int height = bmp.getHeight(); Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565); int pixColor = 0; int pixR = 0; int pixG = 0; int pixB = 0; int newR = 0; int newG = 0; int newB = 0; int[] pixels = new int[width * height]; bmp.getPixels(pixels, 0, width, 0, 0, width, height); for (int i = 0; i < height; i++) { for (int k = 0; k < width; k++) { pixColor = pixels[width * i + k]; pixR = Color.red(pixColor); pixG = Color.green(pixColor); pixB = Color.blue(pixColor); newR = (int) (0.393 * pixR + 0.769 * pixG + 0.189 * pixB); newG = (int) (0.349 * pixR + 0.686 * pixG + 0.168 * pixB); newB = (int) (0.272 * pixR + 0.534 * pixG + 0.131 * pixB); int newColor = Color.argb(255, newR > 255 ? 255 : newR, newG > 255 ? 255 : newG, newB > 255 ? 255 : newB); pixels[width * i + k] = newColor; } } bitmap.setPixels(pixels, 0, width, 0, 0, width, height); return bitmap; } /** * 暖意特效 * * @param bmp * 原图片 * @param centerX * 光源横坐标 * @param centerY * 光源纵坐标 * @return 暖意特效图片 */ public static Bitmap warmthFilter(Bitmap bmp, int centerX, int centerY) { final int width = bmp.getWidth(); final int height = bmp.getHeight(); Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565); int pixR = 0; int pixG = 0; int pixB = 0; int pixColor = 0; int newR = 0; int newG = 0; int newB = 0; int radius = Math.min(centerX, centerY); final float strength = 150F; // 光照强度 100~150 int[] pixels = new int[width * height]; bmp.getPixels(pixels, 0, width, 0, 0, width, height); int pos = 0; for (int i = 1, length = height - 1; i < length; i++) { for (int k = 1, len = width - 1; k < len; k++) { pos = i * width + k; pixColor = pixels[pos]; pixR = Color.red(pixColor); pixG = Color.green(pixColor); pixB = Color.blue(pixColor); newR = pixR; newG = pixG; newB = pixB; // 计算当前点到光照中心的距离，平面座标系中求两点之间的距离 int distance = (int) (Math.pow((centerY - i), 2) + Math.pow(centerX - k, 2)); if (distance < radius * radius) { // 按照距离大小计算增加的光照值 int result = (int) (strength * (1.0 - Math.sqrt(distance) / radius)); newR = pixR + result; newG = pixG + result; newB = pixB + result; } newR = Math.min(255, Math.max(0, newR)); newG = Math.min(255, Math.max(0, newG)); newB = Math.min(255, Math.max(0, newB)); pixels[pos] = Color.argb(255, newR, newG, newB); } } bitmap.setPixels(pixels, 0, width, 0, 0, width, height); return bitmap; } /** * 根据饱和度、色相、亮度调整图片 * * @param bm * 原图片 * @param saturation * 饱和度 * @param hue * 色相 * @param lum * 亮度 * @return 处理后的图片 */ public static Bitmap handleImage(Bitmap bm, int saturation, int hue, int lum) { Bitmap bmp = Bitmap.createBitmap(bm.getWidth(), bm.getHeight(), Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(bmp); Paint paint = new Paint(); paint.setAntiAlias(true); ColorMatrix mLightnessMatrix = new ColorMatrix(); ColorMatrix mSaturationMatrix = new ColorMatrix(); ColorMatrix mHueMatrix = new ColorMatrix(); ColorMatrix mAllMatrix = new ColorMatrix(); float mSaturationValue = saturation * 1.0F / 127; float mHueValue = hue * 1.0F / 127; float mLumValue = (lum - 127) * 1.0F / 127 * 180; mHueMatrix.reset(); mHueMatrix.setScale(mHueValue, mHueValue, mHueValue, 1); mSaturationMatrix.reset(); mSaturationMatrix.setSaturation(mSaturationValue); mLightnessMatrix.reset(); mLightnessMatrix.setRotate(0, mLumValue); mLightnessMatrix.setRotate(1, mLumValue); mLightnessMatrix.setRotate(2, mLumValue); mAllMatrix.reset(); mAllMatrix.postConcat(mHueMatrix); mAllMatrix.postConcat(mSaturationMatrix); mAllMatrix.postConcat(mLightnessMatrix); paint.setColorFilter(new ColorMatrixColorFilter(mAllMatrix)); canvas.drawBitmap(bm, 0, 0, paint); return bmp; } /** * 添加图片外边框 * * @param context * 上下文 * @param bm * 原图片 * @param frameName * 边框名称 * @return 带有边框的图片 */ public static Bitmap combinateFrame(Context context, Bitmap bm, String frameName) { // 原图片的宽高 int imageWidth = bm.getWidth(); int imageHeight = bm.getHeight(); // 边框 Bitmap leftUp = decodeBitmap(context, frameName, 0); Bitmap leftDown = decodeBitmap(context, frameName, 2); Bitmap rightDown = decodeBitmap(context, frameName, 4); Bitmap rightUp = decodeBitmap(context, frameName, 6); Bitmap top = decodeBitmap(context, frameName, 7); Bitmap down = decodeBitmap(context, frameName, 3); Bitmap left = decodeBitmap(context, frameName, 1); Bitmap right = decodeBitmap(context, frameName, 5); Bitmap newBitmap = null; Canvas canvas = null; // 判断大小图片的宽高 int judgeWidth = 0; int judgeHeight = 0; if ("frame7".equals(frameName)) { judgeWidth = leftUp.getWidth() + rightUp.getWidth() + top.getWidth() * 5; judgeHeight = leftUp.getHeight() + leftDown.getHeight() + left.getHeight() * 5; } else if ("frame10".equals(frameName)) { judgeWidth = leftUp.getWidth() + rightUp.getWidth() + top.getWidth() * 5; judgeHeight = leftUp.getHeight() + leftDown.getHeight() + left.getHeight() * 10; } else { judgeWidth = leftUp.getWidth() + rightUp.getWidth() + top.getWidth(); judgeHeight = leftUp.getHeight() + leftDown.getHeight() + left.getHeight(); } // 内边框 if (imageWidth > judgeWidth && imageHeight > judgeHeight) { // 重新定义一个bitmap newBitmap = Bitmap.createBitmap(imageWidth, imageHeight, Config.ARGB_8888); canvas = new Canvas(newBitmap); Paint paint = new Paint(); // 画原图 canvas.drawBitmap(bm, 0, 0, paint); // 上空余宽度 int topWidth = imageWidth - leftUp.getWidth() - rightUp.getWidth(); // 上空余填充个数 int topCount = (int) Math.ceil(topWidth * 1.0f / top.getWidth()); for (int i = 0; i < topCount; i++) { canvas.drawBitmap(top, leftUp.getWidth() + top.getWidth() * i, 0, paint); } // 下空余宽度 int downWidth = imageWidth - leftDown.getWidth() - rightDown.getWidth(); // 下空余填充个数 int downCount = (int) Math.ceil(downWidth * 1.0f / down.getWidth()); for (int i = 0; i < downCount; i++) { canvas.drawBitmap(down, leftDown.getWidth() + down.getWidth() * i, imageHeight - down.getHeight(), paint); } // 左空余高度 int leftHeight = imageHeight - leftUp.getHeight() - leftDown.getHeight(); // 左空余填充个数 int leftCount = (int) Math.ceil(leftHeight * 1.0f / left.getHeight()); for (int i = 0; i < leftCount; i++) { canvas.drawBitmap(left, 0, leftUp.getHeight() + left.getHeight() * i, paint); } // 右空余高度 int rightHeight = imageHeight - rightUp.getHeight() - rightDown.getHeight(); // 右空余填充个数 int rightCount = (int) Math.ceil(rightHeight * 1.0f / right.getHeight()); for (int i = 0; i < rightCount; i++) { canvas.drawBitmap(right, imageWidth - right.getWidth(), rightUp.getHeight() + right.getHeight() * i, paint); } // 画左上角 canvas.drawBitmap(leftUp, 0, 0, paint); // 画左下角 canvas.drawBitmap(leftDown, 0, imageHeight - leftDown.getHeight(), paint); // 画右下角 canvas.drawBitmap(rightDown, imageWidth - rightDown.getWidth(), imageHeight - rightDown.getHeight(), paint); // 画右上角 canvas.drawBitmap(rightUp, imageWidth - rightUp.getWidth(), 0, paint); } else { if ("frame7".equals(frameName)) { imageWidth = leftUp.getWidth() + top.getWidth() * 5 + rightUp.getWidth(); imageHeight = leftUp.getHeight() + left.getHeight() * 5 + leftDown.getHeight(); } else if ("frame10".equals(frameName)) { imageWidth = leftUp.getWidth() + top.getWidth() * 5 + rightUp.getWidth(); imageHeight = leftUp.getHeight() + left.getHeight() * 10 + leftDown.getHeight(); } else { imageWidth = leftUp.getWidth() + top.getWidth() + rightUp.getWidth(); imageHeight = leftUp.getHeight() + left.getHeight() + leftDown.getHeight(); } newBitmap = Bitmap.createBitmap(imageWidth, imageHeight, Config.ARGB_8888); canvas = new Canvas(newBitmap); Paint paint = new Paint(); int newImageWidth = imageWidth - left.getWidth() - right.getWidth() + 5; int newImageHeight = imageHeight - top.getHeight() - down.getHeight() + 5; bm = Bitmap.createScaledBitmap(bm, newImageWidth, newImageHeight, true); canvas.drawBitmap(bm, left.getWidth(), top.getHeight(), paint); if ("frame7".equals(frameName)) { for (int i = 0; i < 5; i++) { canvas.drawBitmap(top, leftUp.getWidth() + top.getWidth() * i, 0, paint); } for (int i = 0; i < 5; i++) { canvas.drawBitmap(left, 0, leftUp.getHeight() + left.getHeight() * i, paint); } for (int i = 0; i < 5; i++) { canvas.drawBitmap(right, imageWidth - right.getWidth(), rightUp.getHeight() + right.getHeight() * i, paint); } for (int i = 0; i < 5; i++) { canvas.drawBitmap(down, leftDown.getWidth() + down.getWidth() * i, imageHeight - down.getHeight(), paint); } canvas.drawBitmap(leftUp, 0, 0, paint); canvas.drawBitmap(rightUp, leftUp.getWidth() + top.getWidth() * 5, 0, paint); canvas.drawBitmap(leftDown, 0, leftUp.getHeight() + left.getHeight() * 5, paint); canvas.drawBitmap(rightDown, imageWidth - rightDown.getWidth(), rightUp.getHeight() + right.getHeight() * 5, paint); } else if ("frame10".equals(frameName)) { for (int i = 0; i < 5; i++) { canvas.drawBitmap(top, leftUp.getWidth() + top.getWidth() * i, 0, paint); } for (int i = 0; i < 10; i++) { canvas.drawBitmap(left, 0, leftUp.getHeight() + left.getHeight() * i, paint); } for (int i = 0; i < 10; i++) { canvas.drawBitmap(right, imageWidth - right.getWidth(), rightUp.getHeight() + right.getHeight() * i, paint); } for (int i = 0; i < 5; i++) { canvas.drawBitmap(down, leftDown.getWidth() + down.getWidth() * i, imageHeight - down.getHeight(), paint); } canvas.drawBitmap(leftUp, 0, 0, paint); canvas.drawBitmap(rightUp, leftUp.getWidth() + top.getWidth() * 5, 0, paint); canvas.drawBitmap(leftDown, 0, leftUp.getHeight() + left.getHeight() * 10, paint); canvas.drawBitmap(rightDown, imageWidth - rightDown.getWidth(), rightUp.getHeight() + right.getHeight() * 10, paint); } else { canvas.drawBitmap(leftUp, 0, 0, paint); canvas.drawBitmap(top, leftUp.getWidth(), 0, paint); canvas.drawBitmap(rightUp, leftUp.getWidth() + top.getWidth(), 0, paint); canvas.drawBitmap(left, 0, leftUp.getHeight(), paint); canvas.drawBitmap(leftDown, 0, leftUp.getHeight() + left.getHeight(), paint); canvas.drawBitmap(right, imageWidth - right.getWidth(), rightUp.getHeight(), paint); canvas.drawBitmap(rightDown, imageWidth - rightDown.getWidth(), rightUp.getHeight() + right.getHeight(), paint); canvas.drawBitmap(down, leftDown.getWidth(), imageHeight - down.getHeight(), paint); } } // 回收 leftUp.recycle(); leftUp = null; leftDown.recycle(); leftDown = null; rightDown.recycle(); rightDown = null; rightUp.recycle(); rightUp = null; top.recycle(); top = null; down.recycle(); down = null; left.recycle(); left = null; right.recycle(); right = null; canvas.save(Canvas.ALL_SAVE_FLAG); canvas.restore(); return newBitmap; } /** * 获取边框图片 * * @param context * 上下文 * @param frameName * 边框名称 * @param position * 边框的类型 * @return 边框图片 */ private static Bitmap decodeBitmap(Context context, String frameName, int position) { try { switch (position) { case 0: return BitmapFactory.decodeStream(context.getAssets().open("frames/" + frameName + "/leftup.png")); case 1: return BitmapFactory.decodeStream(context.getAssets().open("frames/" + frameName + "/left.png")); case 2: return BitmapFactory.decodeStream(context.getAssets().open("frames/" + frameName + "/leftdown.png")); case 3: return BitmapFactory.decodeStream(context.getAssets().open("frames/" + frameName + "/down.png")); case 4: return BitmapFactory.decodeStream(context.getAssets().open("frames/" + frameName + "/rightdown.png")); case 5: return BitmapFactory.decodeStream(context.getAssets().open("frames/" + frameName + "/right.png")); case 6: return BitmapFactory.decodeStream(context.getAssets().open("frames/" + frameName + "/rightup.png")); case 7: return BitmapFactory.decodeStream(context.getAssets().open("frames/" + frameName + "/up.png")); default: return null; } } catch (IOException e) { e.printStackTrace(); return null; } } /** * 添加内边框 * * @param bm * 原图片 * @param frame * 内边框图片 * @return 带有边框的图片 */ public static Bitmap addBigFrame(Bitmap bm, Bitmap frame) { Bitmap newBitmap = Bitmap.createBitmap(bm.getWidth(), bm.getHeight(), Config.ARGB_8888); Canvas canvas = new Canvas(newBitmap); Paint paint = new Paint(); canvas.drawBitmap(bm, 0, 0, paint); frame = Bitmap.createScaledBitmap(frame, bm.getWidth(), bm.getHeight(), true); canvas.drawBitmap(frame, 0, 0, paint); canvas.save(Canvas.ALL_SAVE_FLAG); canvas.restore(); return newBitmap; } /** * 创建一个缩放的图片 * * @param path * 图片地址 * @param w * 图片宽度 * @param h * 图片高度 * @return 缩放后的图片 */ public static Bitmap createBitmap(String path, int w, int h) { try { BitmapFactory.Options opts = new BitmapFactory.Options(); opts.inJustDecodeBounds = true; // 这里是整个方法的关键，inJustDecodeBounds设为true时将不为图片分配内存。 BitmapFactory.decodeFile(path, opts); int srcWidth = opts.outWidth;// 获取图片的原始宽度 int srcHeight = opts.outHeight;// 获取图片原始高度 int destWidth = 0; int destHeight = 0; // 缩放的比例 double ratio = 0.0; if (srcWidth < w || srcHeight < h) { ratio = 0.0; destWidth = srcWidth; destHeight = srcHeight; } else if (srcWidth > srcHeight) {// 按比例计算缩放后的图片大小，maxLength是长或宽允许的最大长度 ratio = (double) srcWidth / w; destWidth = w; destHeight = (int) (srcHeight / ratio); } else { ratio = (double) srcHeight / h; destHeight = h; destWidth = (int) (srcWidth / ratio); } BitmapFactory.Options newOpts = new BitmapFactory.Options(); // 缩放的比例，缩放是很难按准备的比例进行缩放的，目前我只发现只能通过inSampleSize来进行缩放，其值表明缩放的倍数，SDK中建议其值是2的指数值 newOpts.inSampleSize = (int) ratio + 1; // inJustDecodeBounds设为false表示把图片读进内存中 newOpts.inJustDecodeBounds = false; // 设置大小，这个一般是不准确的，是以inSampleSize的为准，但是如果不设置却不能缩放 newOpts.outHeight = destHeight; newOpts.outWidth = destWidth; // 获取缩放后图片 return BitmapFactory.decodeFile(path, newOpts); } catch (Exception e) { // TODO: handle exception return null; } } public static Bitmap createBitmap2(Context context, int id, int w, int h) { try { BitmapFactory.Options opts = new BitmapFactory.Options(); opts.inJustDecodeBounds = true; // 这里是整个方法的关键，inJustDecodeBounds设为true时将不为图片分配内存。 BitmapFactory.decodeResource(context.getResources(), id, opts); int srcWidth = opts.outWidth;// 获取图片的原始宽度 int srcHeight = opts.outHeight;// 获取图片原始高度 int destWidth = 0; int destHeight = 0; // 缩放的比例 double ratio = 0.0; if (srcWidth < w || srcHeight < h) { ratio = 0.0; destWidth = srcWidth; destHeight = srcHeight; } else if (srcWidth > srcHeight) {// 按比例计算缩放后的图片大小，maxLength是长或宽允许的最大长度 ratio = (double) srcWidth / w; destWidth = w; destHeight = (int) (srcHeight / ratio); } else { ratio = (double) srcHeight / h; destHeight = h; destWidth = (int) (srcWidth / ratio); } BitmapFactory.Options newOpts = new BitmapFactory.Options(); // 缩放的比例，缩放是很难按准备的比例进行缩放的，目前我只发现只能通过inSampleSize来进行缩放，其值表明缩放的倍数，SDK中建议其值是2的指数值 newOpts.inSampleSize = (int) ratio + 1; // inJustDecodeBounds设为false表示把图片读进内存中 newOpts.inJustDecodeBounds = false; // 设置大小，这个一般是不准确的，是以inSampleSize的为准，但是如果不设置却不能缩放 newOpts.outHeight = destHeight; newOpts.outWidth = destWidth; // 获取缩放后图片 // return BitmapFactory.decodeFile(path, newOpts); return BitmapFactory.decodeResource(context.getResources(), id, newOpts); } catch (Exception e) { // TODO: handle exception return null; } } }
