Android: creating a Bitmap with SurfaceView content

Question

I'm afraid to already have the unfortunate answer to this question but just in case... I'm using a SurfaceView to do some image processing with bitmaps (lights and colors modifications) and I would need to import the modified bitmap (i.e. the content of the SurfaceView) in a new bitmap so that I can save it as an image file.

I've been looking around and it seems that it's possible to get a bitmap from View.getDrawingCache() but it doesn't work with SurfaceView. All I get is an empty bitmap.

Is there any solution to this?

Thanks

score 9 · Answer 1 · answered Jan 11 '19 at 19:40

For API levels >=24, use the PixelCopy API. Here's an example inside an ImageView:

public void DrawBitmap(){
    Bitmap surfaceBitmap = Bitmap.createBitmap(600, 600, Bitmap.Config.ARGB_8888);
    PixelCopy.OnPixelCopyFinishedListener listener = copyResult -> {
        // success/failure callback
    };

    PixelCopy.request(YourSurfaceView, surfaceBitmap,listener,getHandler());
    // visualize the retrieved bitmap on your imageview
    setImageBitmap(plotBitmap);
    }
}

score 8 · Answer 2 · answered Jan 20 '11 at 02:24

8

Can you draw your SurfaceView onto a Canvas that's backed by a Bitmap?

    // be sure to call the createBitmap that returns a mutable Bitmap
    Bitmap b = Bitmap.createBitmap(100, 100, Bitmap.Config.ARGB_8888); 
    Canvas c = new Canvas(b);
    yourSurfaceView.draw(c);

answered Jan 20 '11 at 02:24

idbrii

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I wanted to use this solution but it's not possible with SurfaceViews because the drawing process is done in a thread and the canvas is obtained from the SurfaceHolder. It is used this way: canvas = surfaceHolder.lockCanvas(null); synchronized(surfaceHolder) { doDraw(canvas); } – Nicolas P. Jan 20 '11 at 02:46
8

Problem solved. I changed the SurfaceView to a simple custom View. Then, enabling the drawingCache (setDrawingCacheEnabled(true)) when the view is created, I'm able to retrieve a bitmap calling the getDrawingCache() method. – Nicolas P. Jan 21 '11 at 18:54
for your first comment, couldn't you just call doDraw with the bitmap-backed Canvas? `if (screenGrab) { doDraw(c_fromMyPost); } else { doDraw(canvas_fromYourApp); }` – idbrii Jan 22 '11 at 03:12

score 3 · Answer 3 · edited May 23 '17 at 10:34

3

There is no simple way to capture frames of SurfaceView, so you can consider using TextureView instead of SurfaceView: the Bitmap can be retrieved using textureView.getBitmap() method.

edited May 23 '17 at 10:34

Community

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answered Sep 20 '16 at 14:10

Andrew Vovk

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score 1 · Answer 4 · answered Apr 25 '21 at 07:30

1

Just grab the source code for SurfaceView and modify it to give you access to the underlying bitmap.

answered Apr 25 '21 at 07:30

Johann

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That's an interesting solution. Do you mean editing the Android Sdk and recompiling? You could also just extend the SurfaceView. How else can I modify the source code to give me access to the Bitmap? – Cyrill Feb 20 '22 at 22:04

Android: creating a Bitmap with SurfaceView content

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