android - 如何在 Android 中为图像添加水印效果？

Question

我有一个带框架的图像，我需要添加水印效果。我该怎么做？

Answer 1

我在这里找到了关于 Android 图像处理的很棒的教程。

public static Bitmap mark(Bitmap src, String watermark, Point location, Color color, int alpha, int size, boolean underline) {
    int w = src.getWidth();
    int h = src.getHeight();
    Bitmap result = Bitmap.createBitmap(w, h, src.getConfig());

    Canvas canvas = new Canvas(result);
    canvas.drawBitmap(src, 0, 0, null);

    Paint paint = new Paint();
    paint.setColor(color);
    paint.setAlpha(alpha);
    paint.setTextSize(size);
    paint.setAntiAlias(true);
    paint.setUnderlineText(underline);
    canvas.drawText(watermark, location.x, location.y, paint);

    return result;
}

感谢 Pete Houston，他分享了有关基本图像处理的有用教程。

Answer 2

供其他人参考，如果您想在图像顶部添加应用程序的徽标（位于可绘制文件夹中），请使用以下方法：

private Bitmap addWaterMark(Bitmap src) {
        int w = src.getWidth();
        int h = src.getHeight();
        Bitmap result = Bitmap.createBitmap(w, h, src.getConfig());
        Canvas canvas = new Canvas(result);
        canvas.drawBitmap(src, 0, 0, null);

        Bitmap waterMark = BitmapFactory.decodeResource(mContext.getResources(), R.drawable.logo);
        canvas.drawBitmap(waterMark, 0, 0, null);

        return result;
    }

Answer 3

如果有人还在寻找这个，我在这里找到了一个很好的解决方案

它在右下角添加了一个水印，并根据我正在寻找的源图像对其进行缩放。

/**
 * Embeds an image watermark over a source image to produce
 * a watermarked one.
 * @param source The source image where watermark should be placed
 * @param watermark Watermark image to place
 * @param ratio A float value < 1 to give the ratio of watermark's height to image's height,
 *             try changing this from 0.20 to 0.60 to obtain right results
 */
public static Bitmap addWatermark(Bitmap source, Bitmap watermark, float ratio) {
    Canvas canvas;
    Paint paint;
    Bitmap bmp;
    Matrix matrix;
    RectF r;

    int width, height;
    float scale;

    width = source.getWidth();
    height = source.getHeight();

    // Create the new bitmap
    bmp = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    paint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.DITHER_FLAG | Paint.FILTER_BITMAP_FLAG);

    // Copy the original bitmap into the new one
    canvas = new Canvas(bmp);
    canvas.drawBitmap(source, 0, 0, paint);

    // Scale the watermark to be approximately to the ratio given of the source image height
    scale = (float) (((float) height * ratio) / (float) watermark.getHeight());

    // Create the matrix
    matrix = new Matrix();
    matrix.postScale(scale, scale);

    // Determine the post-scaled size of the watermark
    r = new RectF(0, 0, watermark.getWidth(), watermark.getHeight());
    matrix.mapRect(r);

    // Move the watermark to the bottom right corner
    matrix.postTranslate(width - r.width(), height - r.height());

    // Draw the watermark
    canvas.drawBitmap(watermark, matrix, paint);

    return bmp;
}

并且评论很好，这是一个巨大的优势！

Answer 4

看来你正在寻找一个waterrippleeffect像这个一样的。查看完整的源代码。还要检查截图效果如何。

Answer 5

您可以使用androidWM在图像中添加水印，即使有不可见的水印：

添加依赖：

dependencies {
  ...
  implementation 'com.huangyz0918:androidwm:0.2.3'
  ...
}

和java代码：

 WatermarkText watermarkText = new WatermarkText(“Hello World”)
                    .setPositionX(0.5) 
                    .setPositionY(0.5) 
                    .setTextAlpha(100) 
                    .setTextColor(Color.WHITE) 
                    .setTextFont(R.font.champagne) 
                    .setTextShadow(0.1f, 5, 5, Color.BLUE); 

 WatermarkBuilder.create(this, backgroundBitmap) 
                    .loadWatermarkText(watermarkText) 
                    .getWatermark() 
                    .setToImageView(backgroundView); 

您可以像这样轻松添加图像类型的水印或文本水印，并且库大小小于 30Kb。

Answer 6

使用框架布局。将两个图像视图放在框架布局内并指定水印图像视图的位置。