给图片添加水印的基本思路都是载入原图，添加文字或者载入水印图片，保存图片这三个部分
添加水印图片：
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private Bitmap createWaterMaskImage(Context gContext, Bitmap src, Bitmap watermark) { String tag = "createBitmap"; Log.d(tag, "create a new bitmap"); if (src == null) { return null; } int w = src.getWidth(); int h = src.getHeight(); int ww = watermark.getWidth(); int wh = watermark.getHeight(); // create the new blank bitmap 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); // draw src into cv.drawBitmap(src, 0, 0, null);// 在 0，0坐标开始画入src // draw watermark into cv.drawBitmap(watermark, 20, 20, null);// 在src的右下角画入水印 // save all clip cv.save(Canvas.ALL_SAVE_FLAG);// 保存 // store cv.restore();// 存储 return newb; } |
添加文字
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public static Bitmap scaleWithWH(Bitmap src, double w, double h) { if (w == 0 || h == 0 || src == null) { return src; } else { // 记录src的宽高 int width = src.getWidth(); int height = src.getHeight(); // 创建一个matrix容器 Matrix matrix = new Matrix(); // 计算缩放比例 float scaleWidth = (float) (w / width); float scaleHeight = (float) (h / height); // 开始缩放 matrix.postScale(scaleWidth, scaleHeight); // 创建缩放后的图片 return Bitmap.createBitmap(src, 0, 0, width, height, matrix, true); } } public Bitmap drawTextToBitmap(Context gContext, int gResId, String gText) { Resources resources = gContext.getResources(); float scale = resources.getDisplayMetrics().density; Bitmap bitmap = BitmapFactory.decodeResource(resources, gResId); bitmap = scaleWithWH(bitmap, 300*scale, 300*scale); 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.RED); paint.setTextSize((int) (18 * scale)); paint.setDither(true); //获取跟清晰的图像采样 paint.setFilterBitmap(true);//过滤一些 Rect bounds = new Rect(); paint.getTextBounds(gText, 0, gText.length(), bounds); int x = 30; int y = 30; canvas.drawText(gText, x * scale, y * scale, paint); return bitmap; } |