Android Bitmap 图片处理工具类

	public static Bitmap getImg(String path,String picName) {
		if (!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
			return null;
		}
		try {
			File file = new File(path,picName + ".png");
			FileInputStream inputStream = new FileInputStream(file);
			byte[] b = new byte[inputStream.available()];
			inputStream.read(b);
			Bitmap bitmap = BitmapFactory.decodeByteArray(b,b.length);
			return bitmap;
		} catch (Exception e) {
			return null;
		}
	}

public static Bitmap getImageByNet(String urlpath) throws Exception {
        URL url = new URL(urlpath);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setRequestMethod("GET");
        conn.setConnectTimeout(5 * 1000);
        Bitmap bitmap = null;
        if (conn.getResponseCode() == 200) {
            InputStream inputStream = conn.getInputStream();
            bitmap = BitmapFactory.decodeStream(inputStream);
        }
        return bitmap;
    }

将两个bitmap对象整合并保存为一张图片

	public Bitmap combineBitmap(Bitmap background,Bitmap foreground) {
		//第一张图片的宽高
		int bgWidth = background.getWidth();
		int bgHeight = background.getHeight();
		//第二章图片的宽高
		int fgWidth = foreground.getWidth();
		int fgHeight = foreground.getHeight();
		//创建一个新的bitmao  高度等于两张高度的总和 用来竖列拼接
		Bitmap newmap = Bitmap.createBitmap(bgWidth,bgHeight + fgHeight,android.graphics.Bitmap.Config.ARGB_8888);
		Canvas canvas = new Canvas(newmap);
		//画上第一张图片
		canvas.drawBitmap(background,null);
		//从第一张图片的下边开始画入第二张图片
		canvas.drawBitmap(foreground,bgHeight,null);
		return newmap;
	}

Bitmap旋转一定角度

	public static Bitmap rotate(Bitmap b,int degrees) {
		if (degrees != 0 && b != null) {
			Matrix m = new Matrix();
			m.setRotate(degrees,(float) b.getWidth() / 2,(float) b.getHeight() / 2);
			try {
				Bitmap b2 = Bitmap.createBitmap(b,b.getWidth(),b.getHeight(),m,true);
				return b2;// 正常情况下返回旋转角度的图
			} catch (OutOfMemoryError ex) {
				return b;// 内存溢出返回原图
			} finally {
				b.recycle();// 释放资源
			}
		}
		return b;
	}

	public static Bitmap getRoundedCornerBitmap(Bitmap bitmap,float roundPx) {
		if (bitmap == null) {
			return bitmap;
		}
		try {
			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,bitmap.getWidth(),bitmap.getHeight());
			final RectF rectF = new RectF(rect);
			paint.setAntiAlias(true);
			canvas.drawARGB(0,0);
			paint.setColor(color);
			canvas.drawRoundRect(rectF,roundPx,paint);
			paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
			canvas.drawBitmap(bitmap,rect,paint);
			return output;
		} catch (OutOfMemoryError e) {
			// TODO: handle exception
			System.gc();
			return null;
		}
	}

	public static Bitmap getBitmapFromView(View view) {
		view.destroyDrawingCache();
		view.measure(View.MeasureSpec.makeMeasureSpec(0,View.MeasureSpec.UNSPECIFIED),View.MeasureSpec
				.makeMeasureSpec(0,View.MeasureSpec.UNSPECIFIED));
		view.layout(0,view.getMeasuredWidth(),view.getMeasuredHeight());
		view.setDrawingCacheEnabled(true);
		Bitmap bitmap = view.getDrawingCache(true);
		return bitmap;
	}

	public static Bitmap watermarkBitmap(Bitmap src,Bitmap watermark,String title) {
		if (src == null) {
			return null;
		}
		int w = src.getWidth();
		int h = src.getHeight();
		// 需要处理图片太大造成的内存超过的问题,这里我的图片很小所以不写相应代码了
		Bitmap newb = Bitmap.createBitmap(w,h,Config.ARGB_8888);// 创建一个新的和SRC长度宽度一样的位图
		Canvas cv = new Canvas(newb);
		cv.drawBitmap(src,null);// 在 0，0坐标开始画入src
		Paint paint = new Paint();
		// 加入图片
		if (watermark != null) {
			int ww = watermark.getWidth();
			int wh = watermark.getHeight();
			paint.setAlpha(50);
			cv.drawBitmap(watermark,w - ww + 5,h - wh + 5,paint);// 在src的右下角画入水印
		}
		// 加入文字
		if (title != null) {
			String familyName = "宋体";
			Typeface font = Typeface.create(familyName,Typeface.BOLD);
			TextPaint textPaint = new TextPaint();
			textPaint.setColor(Color.RED);
			textPaint.setTypeface(font);
			textPaint.setTextSize(22);
			// 这里是自动换行的
			StaticLayout layout = new StaticLayout(title,textPaint,w,Alignment.ALIGN_NORMAL,1.0F,0.0F,true);
			layout.draw(cv);
			// 文字就加左上角算了
			// cv.drawText(title,40,paint);
		}
		cv.save(Canvas.ALL_SAVE_FLAG);// 保存
		cv.restore();// 存储
		return newb;
	}

等比例压缩图片

      public static Bitmap getBitmap(Bitmap bitmap,int screenWidth,int screenHight) {
		int w = bitmap.getWidth();
		int h = bitmap.getHeight();
		
		Matrix matrix = new Matrix();
		float scale = (float) screenWidth / w;
		float scale2 = (float) screenHight / h;
		
		//取比例小的值 可以把图片完全缩放在屏幕内
		scale = scale < scale2 ? scale : scale2;

		// 都按照宽度scale 保证图片不变形.根据宽度来确定高度
		matrix.postScale(scale,scale);
		// w,h是原图的属性.
		return Bitmap.createBitmap(bitmap,matrix,true);
	}

以最省内存的方式读取本地资源的图片

        public static Bitmap ReadBitmapById(Context context,int drawableId,int screenHight) {
		BitmapFactory.Options options = new BitmapFactory.Options();
		options.inPreferredConfig = Config.ARGB_8888;
		options.inInputShareable = true;
		options.inPurgeable = true;
		InputStream stream = context.getResources().openRawResource(drawableId);
		Bitmap bitmap = BitmapFactory.decodeStream(stream,null,options);
		return getBitmap(bitmap,screenWidth,screenHight);
	}