Grey scale conversion not functioning properly

[DougRogers]

Attached image does not convert to QImage properly.

[fabiencastan]

Yes, you're right.
It has been created for usage in Meshroom for photogrammetry and we display grayscale images (depth maps) with a jet color map.

We need to add an additional check here:
https://github.com/alicevision/QtOIIO/blob/develop/src/imageIOHandler/QtOIIOHandler.cpp#L65
Maybe just based on the filename as there is no way to have options.

[DougRogers]

It still does not work if convertGrayscaleToJetColorMap is set to false.

You will need something like this to support grey scale

            const oiio::TypeDesc typeDesc = oiio::TypeDesc::UINT8;
            oiio::ImageSpec requestedSpec(inSpec.width, inSpec.height, nchannels, typeDesc);

            oiio::ROI exportROI = inBuf.roi();
            exportROI.chbegin   = 0;
            exportROI.chend     = nchannels;

            // qDebug() << "[QtOIIO] fill output QImage";

            std::vector<uint8_t> conversionBuffer(inSpec.height * inSpec.scanline_bytes());
            inBuf.get_pixels(exportROI, typeDesc, conversionBuffer.data());
            auto src = conversionBuffer.data();
            auto dst = result.bits();

            for (int y = 0; y < inSpec.height; ++y)
            {
                memcpy(dst, src, inSpec.width);
                src += inSpec.scanline_bytes();
                dst += result.bytesPerLine();
            }

[fabiencastan]

There is also some commented code:
https://github.com/alicevision/QtOIIO/blob/develop/src/imageIOHandler/QtOIIOHandler.cpp#L197

[DougRogers]

Does uncommenting out that code and setting the convertGrayscaleToJetColorMap flag to false, load the test image for you?

[fabiencastan]

I have not tested it.