Is this library correct for my use-case?

[TheMachineHere]

So basically, I'm trying to build an app where you can colour the walls in real-time.

I was trying to do Sobel Edge Detection, get the edges from that and then floodfill in the space. I am not sure if this is the correct library i should be using.

Any help would be appreciated?

[Windsander]

Hi guys, nice for asking ;p If u just want to use Sobel Edge Detection to modify a single picture, you can use this lib like this:

@Override
public void onCreate(final Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity);

    // prepare surface.
    mRecorderViews = (FilterRecoderView) findViewById(R.id.vp_video_recorder_gl);
    
    // prepare the filter you want to use
    final GPUImageContrastFilter contrastFilter = new GPUImageContrastFilter(1.0f);
    contrastFilter.setContrast(contrastValue);
    
    // bind to PureImageManager and render
    PureImageManager.init(context)
                    .setGLSurfaceView(mRecorderViews)
                    .setScaleType(GPUImage.ScaleType.CENTER_INSIDE)
                    .setImage(mUri)
                    .setFilter(contrastFilter)
                    .requestRender();
}

But the filter you use to deal with the input frame buffer need to be defined by yourself. There has two ready-made Sobel Edge Detection filter of deferent type, one is a pure Sobel, you can find it at

cn.co.willow.android.ultimate.gpuimage.core_render_filter.image_enhance_filter.filter_3x3_sampling.GPUImageDirectionalSobelEdgeDetectionFilter

, another is a filter group

cn.co.willow.android.ultimate.gpuimage.core_render_filter.recommend_effect_filter_group.GPUImageSobelEdgeDetection 

I suggest you consult this two, especial the second one. The purpose of this lib is to deal video/audio stream with filter or staff like that.

[TheMachineHere]

Hey @Windsander . Thanks for the reply, i really appreciate it.

A couple of questions for you.

1. If i want to define my own filters (with my own shaders), how can i do that?
2. If i want to floodfill a specific frame how can i do that? I don't think we can use shaders/gpu to flood fill, so is there a way to get each frame data and do some cpu processing on that?

Also, the code you gave me.

     @Override
     public void onCreate(final Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity);

        // prepare surface.
        mRecorderViews = (FilterRecoderView) findViewById(R.id.vp_video_recorder_gl);
        
        // prepare the filter you want to use
        final GPUImageContrastFilter contrastFilter = new GPUImageContrastFilter(1.0f);
        contrastFilter.setContrast(contrastValue);
        
        // bind to PureImageManager and render
        PureImageManager.init(context)
                        .setGLSurfaceView(mRecorderViews)
                        .setScaleType(GPUImage.ScaleType.CENTER_INSIDE)
                        .setImage(mUri)
                        .setFilter(contrastFilter)
                        .requestRender();
     }

If I want to get frames from a camera continuously, should I be using this code? Should i be calling .setImage(cameraFrameBitmap) ? Or should i be doing something else?

Thank you.

:)