android ImageUtils 图片处理工具类

	/**
	 * 添加文字到图片，类似水印文字。
	 * @param gContext
	 * @param gResId
	 * @param gText
	 * @return
	 */
	public static Bitmap drawTextToBitmap(Context gContext, int gResId, String gText) {
		Resources resources = gContext.getResources();
		float scale = resources.getDisplayMetrics().density;
		Bitmap bitmap = BitmapFactory.decodeResource(resources, gResId);

		android.graphics.Bitmap.Config bitmapConfig = bitmap.getConfig();
		// set default bitmap config if none
		if (bitmapConfig == null) {
			bitmapConfig = android.graphics.Bitmap.Config.ARGB_8888;
		}
		// resource bitmaps are imutable,
		// so we need to convert it to mutable one
		bitmap = bitmap.copy(bitmapConfig, true);

		Canvas canvas = new Canvas(bitmap);
		// new antialised Paint
		Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
		// text color - #3D3D3D
		paint.setColor(Color.rgb(61,61,61));
		// text size in pixels
		paint.setTextSize((int) (14 * scale*5));
		// text shadow
		paint.setShadowLayer(1f, 0f, 1f, Color.WHITE);

		// draw text to the Canvas center
		Rect bounds = new Rect();
		paint.getTextBounds(gText, 0, gText.length(), bounds);
//		int x = (bitmap.getWidth() - bounds.width()) / 2;
//		int y = (bitmap.getHeight() + bounds.height()) / 2;
		//draw  text  to the bottom
		int x = (bitmap.getWidth() - bounds.width())/10*9 ;
		int y = (bitmap.getHeight() + bounds.height())/10*9;
		canvas.drawText(gText, x , y, paint);

		return bitmap;
	}