Qt EGLFS dithering for 18-bit color display

diegor

Hi,

we have an i.MX8M Plus board for which we prepared a Boot to Qt based OS with Qt 5.15.
The board has a 18-bit color LVDS display. As the color depth of the display is limited to just 6 bits per color, we'd like to enable dithering, otherwise color gradients will show color banding (https://en.wikipedia.org/wiki/Colour_banding).
For an understanding of what I'm trying to achieve please have a look at:
https://community.nxp.com/t5/i-MX-Processors/imx6-android-dithering-24bit-graphics-on-18bit-panel/m-p/477590/highlight/true#M75826

I've tried to adjust the values in /etc/default/qt according to:
https://doc.qt.io/qt-5/embedded-linux.html#eglfs
In particular I've changed the values of QT_QPA_EGLFS_DEPTH and QT_QPA_EGLFS_FORCE888, but no combination seemed to enable dithering.

Is there any Qt EGLFS or Boot to Qt setting that allows to enable and configure dithering?

Thanks in advance
Diego

SGaist

Hi,

Boot2Qt being a commercial product, I would recommend to contact the Qt Company directly for support.

diegor

@SGaist Thanks, we'll try that.