Android Bitmap 图片处理工具类详解手机开发

	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, 0, 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, 0, 0, null); 
		//从第一张图片的下边开始画入第二张图片 
		canvas.drawBitmap(foreground, 0, 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, 0, 0, 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, 0, bitmap.getWidth(), 
					bitmap.getHeight()); 
			final RectF rectF = new RectF(rect); 
			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; 
		} 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, 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, 0, 0, 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,0,40,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, 0, 0, w, h, 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 screenWidth, 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); 	}