LUMINANCE doesn't work for Textures

[ghost]

For kinect (specifically) but in general:

If you have a LUMINANCE array ( say, from the depth camera ) that comes in as 16bits per pixel, you can store that in an ofShortPixels.

and later, load this into a texture like this:

depthTex.loadData(depthPixels.getPixels(), depthFrameDescription.width, depthFrameDescription.height, GL_LUMINANCE);

However in RT, Textures defined as GL_LUMINANCE fail to display properly.

Is this maybe an Angle thing? Or can we write up a workaround for RT?

Trying to get an ofxKinectV2RT helper class going for this weekend hackfest, thanks...

[stammen]

Try GL_RED.

Look at openframeworks#2952

[ghost]

So, GL_RED didn't work, but I got GL_LUMINANCE to work by massaging the data better. Closing the issue.

Here is the combo that ended up working and displaying (partial code from the KinectV2 Helper class I'm writing):

ofTexture& getDepthFrameAsTexture(DepthFrame^ depthFrame)
{
if ( !depthFrameArray.isAllocated() ) {
_depthFrameArray = ref new Platform::Array(depthFrame->FrameDescription->LengthInPixels);
}

if ( _depthFramePixels.isAllocated() ) {
    _depthFramePixels.allocate(
        depthFrame->FrameDescription->Width,
        depthFrame->FrameDescription->Height,
        OF_IMAGE_GRAYSCALE);
}

// STORE THE DEPTH FRAME INTO AN ARRAY
depthFrame->CopyFrameDataToArray(_depthFrameArray);

// IF YOU WANT TO CONVERT THE ARRAY INTO AN ofPixels, DO THIS:
for (int i = 0; i < _depthFrameArray->Length; i++)
{
    _depthFramePixels.getPixels()[i] = depthValueToGreyscaleTable[
                ofClamp(_depthFrameArray[i], 
                0, 
                depthValueToGreyscaleTable.size() - 1)];
}

// AND TO CONVERT THE ofPixels INTO A TEXTURE, DO THIS:
if (!_depthFrameTexture.isAllocated())
{
    _depthFrameTexture.allocate(
        depthFrame->FrameDescription->Width,
        depthFrame->FrameDescription->Height,
        GL_LUMINANCE
        );
}

_depthFrameTexture.loadData(tempPixels);
return _depthFrameTexture;

}

// HERE IS THE LOOKUP TABLE THAT CONVERTS THE UINT16 DEPTH VALUE IN MM TO A MAPPED CHAR FOR GREYSCALE
void ofxKinectV2RT::updateDepthValueToGreyscaleTable()
{
unsigned char nearColor = 255;
unsigned char farColor = 0;
unsigned int maxDepthLevels = 5001;
depthValueToGreyscaleTable.resize(maxDepthLevels);
depthValueToGreyscaleTable[0] = 0;
for (unsigned int i = 1; i < maxDepthLevels; i++)
{
depthValueToGreyscaleTable[i] = ofMap(i, 500, 4000, nearColor, farColor, true);
}
}