Please explain this color banding puzzle

So I bought the LP156WF6-SPB1 replacement LCD display. It's a 6-bit display with 262k colors. When I install it in my laptop, the picture quality is fine. Color banding is reduced because of dithering. But when I use it outside of my laptop, connected to an HDMI eDP driver board like this, the screen has lots of color banding. Keep in mind it's the very same panel. It seems when connected to the eDP driver board, there is no dithering. Why is that and is it possible to somehow force dithering with the eDP driver board or convert the HDMI signal to use dithering? Please help.

 

Dithering is done before the signal is sent to the display. The display only shows the color pixel for pixel as signaled to by the hardware. The hardware, accoring to interface etc., can have pixels dithered either vi software or the hardware itself before the signal output to the display.

 

So lets say I connect a PS4 to the display and there is color banding. Is it the PS4's fault or is it the eDP driver board's fault?

 

With a 6 bit display banding is almost inevitable. Even under dithering unless there is a large area between graduations either banding and/or color inaccuracy/inconsistency will exist. Some results will be better than others as far as a PS4 your best bet is to just match the display hardware to the output specs of the console. Just don't spend tons of money overdoing it. The output is always subject to the weakest link in the system.

 

Well, the dithered picture I get when installed in my laptop is absolutely fine. There is still a bit of color banding, but it's not very noticable. Basically, all I want is to use the same panel for my PS4 without color banding spoilering the fun. My PS4 doesn't have any video settings other than limited and full RGB as well as HDR mode, but they don't reduce the color banding. On regular 6-bit monitors, even on ones with TN panels, the picture is dithered and looks good. So there must be something between the PS4 and the panel to apply that prevents color banding, some kind of a converter or something. Is it possible to reprogram an HDMI eDP driver board to force dithered output?

 

That is done when the seller of the HDMI to eDP board programs it, maybe you can dig some info on how they are programmed, in the laptop you can usually change the bpp in BIOS(if it is unlocked), with option usually ranging from 18, 24 and 32 bits per pixel, I have messed around with those settings and I always think that the image when set to 24/32 bits looks better/more vivid.

It might be that your adapter board is set for 6 bits because the seller will pull the datasheet for the display, see 6 bits and just set that on the controller.