Merge two bitmaps in android

问题:

I want to merge two bitmaps, here is my code

// Camera arg conversion to Bitmap
                    Bitmap cameraBitmap = BitmapFactory.decodeByteArray(arg0, 0,
                            arg0.length);
                    Bitmap back = Bitmap.createBitmap(cameraBitmap.getWidth(),
                        cameraBitmap.getHeight(), Bitmap.Config.ARGB_8888);
                    Canvas cam = new Canvas(back);
                    cam.drawBitmap(cameraBitmap, matrix, null);


                    // FrameLayout to Bitmap
                    FrameLayout mainLayout = (FrameLayout) findViewById(R.id.frame);
                    Bitmap foreground = Bitmap.createBitmap(mainLayout.getWidth(),
                            mainLayout.getHeight(), Bitmap.Config.ARGB_8888);
                    Canvas c = new Canvas(foreground);
                    mainLayout.draw(c);

                    Bitmap cs = null;
                    cs = Bitmap.createBitmap(foreground.getWidth(), cameraBitmap.getHeight(), Bitmap.Config.ARGB_8888); 

                    Canvas comboImage = new Canvas(cs); 
                    comboImage.drawBitmap(cameraBitmap, 0f, 0f, null); 
                    comboImage.drawBitmap(foreground, 0f, cameraBitmap.getHeight(), null); 

                    FileOutputStream fos = null;
                    try {
                        fos = new FileOutputStream(file);
                        if (fos != null) {
                            cs.compress(Bitmap.CompressFormat.PNG, 90, fos);
                            fos.close();
                        }
                    } catch (Exception e) {
                        e.printStackTrace();
                    }   

The camera image should become background, and foreground as top image. I've tried from Combining 2 Images in Android using Canvas but it didn't help me. Any idea.? Thanks

回答1:

From your example, you forgot to add the next lines:

 comboImage.drawBitmap(c, 0f, 0f, null); 
 comboImage.drawBitmap(s, 0f, c.getHeight(), null);

In your example above you don't draw your image in the canvas, and that is the problem. You can think that your canvas i your sketchbook. For now you didn't paint anything, and you ask yourself, way I can't see any colors.

So, for my advice, first create the two bitmaps, then, do the next thing:

c.drawBitmap(cameraBitmap, top point, left point, null);
c.drawBitmap(foreground, top point, left point, null); 

You can also do this by first create the drawable objects from your bitmaps, like in the next code:

Drawable cameraBitmap = BitmapDrawable(cameraBitmap);
Drawable foreground= BitmapDrawable(foreground);

Then when you have the drawable objects, you can set thier bounds, and that way you set where do you want to show that image.

cameraBitmap.setBounds(left, top, right, bottom);
foreground.setBounds(left, top, right, bottom);

and finally draw that on the canvas:

cameraBitmap.draw(canvas);
foreground.draw(canvas);

EDIT:

This is an example, use this to understand your implementation:

    Bitmap bitmap = null;
    try {

        bitmap = Bitmap.createBitmap(500, 500, Config.ARGB_8888);
        Canvas c = new Canvas(bitmap);
        Resources res = getResources();


        Bitmap bitmap1 = BitmapFactory.decodeResource(res, R.drawable.test1); //blue

        Bitmap bitmap2 = BitmapFactory.decodeResource(res, R.drawable.test2); //green
        Drawable drawable1 = new BitmapDrawable(bitmap1);
        Drawable drawable2 = new BitmapDrawable(bitmap2);


        drawable1.setBounds(100, 100, 400, 400);
        drawable2.setBounds(150, 150, 350, 350);
        drawable1.draw(c);
        drawable2.draw(c);


    } catch (Exception e) {
    }
    return bitmap;

This is what I get from the code above:

回答2:

Please note that the BitmapDrawable(Bitmap) has been deprecated. Kinldy check this for the alternative.

BitmapDrawable(Bitmap bitmap) This constructor was deprecated in API level 4. Use BitmapDrawable(Resources, Bitmap) to ensure that the drawable has correctly set its target density.

回答3:

Resize watermark image same size as original image

Uri bmpUri1 = getLocalBitmapUri(ivImage);
Uri bmpUri2 = getLocalBitmapUri(watermark_imageview);

try {
    bm1 = BitmapFactory.decodeStream(
            getContentResolver().openInputStream(bmpUri1));
    bm2 = BitmapFactory.decodeStream(
            getContentResolver().openInputStream(bmpUri2));

    Bitmap bmOverlay = Bitmap.createBitmap(bm1.getWidth(), bm1.getHeight(), bm1.getConfig());
    bm2 = Bitmap.createScaledBitmap(bm2, bm1.getWidth(), bm1.getHeight(),
            true);

    Canvas canvas = new Canvas(bmOverlay);
    canvas.drawBitmap(bm1, 0,0, null);
    canvas.drawBitmap(bm2, 0,0, null);
    watermarkimage.setVisibility(View.GONE);
    im =new ImageView(ImageClick.this);
    im.setImageBitmap(bmOverlay);
    bmpUri = getLocalBitmapUri(im);
} catch (FileNotFoundException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}

private Uri getLocalBitmapUri(ImageView imageView) {
    Drawable drawable = imageView.getDrawable();
    Bitmap bmp = null;
    if (drawable instanceof BitmapDrawable){
        bmp = ((BitmapDrawable) imageView.getDrawable()).getBitmap();
    } else {
        return null;
    }
    // Store image to default external storage directory
    Uri bmpUri = null;
    try {
        File file =  new File(Environment.getExternalStoragePublicDirectory(
                Environment.DIRECTORY_DOWNLOADS), "share_image_" + System.currentTimeMillis() + ".png");
        file.getParentFile().mkdirs();
        FileOutputStream out = new FileOutputStream(file);
        bmp.compress(Bitmap.CompressFormat.PNG, 90, out);
        out.close();
        bmpUri = Uri.fromFile(file);
    } catch (IOException e) {
        e.printStackTrace();
    }
    return bmpUri;
}

回答4:

Merging Two Bitmap vertically when one is large and second is small
follow this method

 public Bitmap finalcombieimage(Bitmap c, Bitmap s) {
    Bitmap cs = null;
    DisplayMetrics metrics = getBaseContext().getResources().getDisplayMetrics();
    int width = metrics.widthPixels;
    int height = metrics.heightPixels;
    cs = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    Canvas comboImage = new Canvas(cs);
    Rect dest1 = new Rect(0, 0, width, height); // left,top,right,bottom
    comboImage.drawBitmap(c, null, dest1, null);
    Rect dest2 = new Rect(0, height-400 / 2, width, height);
    comboImage.drawBitmap(s, null, dest2, null);
    return cs;
}