> so the banding is just the dithering required to display

I know what you're trying to say, but this sounds weird. Dithering is a technique employed to PREVENT banding, it does not cause banding.

Really? Apple sold the device as capable of displaying "millions of colors" which you don't get to with 6 bits per pixel.

Yes, it's an LG LM171W02-TTA1 which is a 6-bit TN panel; most (all?) TN panels of that era were 6-bit at best, so it could only display ~256k colors

It sounds like you're disagreeing, but GP is right per https://support.apple.com/en-us/112313

> 15-inch (viewable) TFT active-matrix LCD, 1024 by 768 pixels, millions of colors

I'm not super familiar with macs, but AFAICT that's the product being described here.

The "millions of colors" was a part of a lawsuit by some photographers who found out it wasn't actually millions.

https://appleinsider.com/articles/08/03/26/apple_settles_mil...

Ah! Okay, that explains the dissonance.

It's most definitely a LM171W02 panel in the iMac G4 which is definitely a 6-bit panel, you can see the specs here: https://www.panelook.com/modelsearch.php?keyword=LM171W02&se... all of the LM171W02 panel family are 6-bit (notice the colors column lists 262k)

Edit: I see you linked to the entire G4 lineup specs. The 15" is a LM151X2 and also has only 262k colors: https://www.panelook.com/modelsearch.php?keyword=LM151X2&sea...

but the 20" is a LM201U04 with an IPS panel that could display millions of colors with 8 bits per channel https://www.panelook.com/modelsearch.php?keyword=LM201U04&se...

so we can assume that Apple is simply using dithering to count as "millions of colors" on the lower models

Okay fair enough, but then... did Apple just straight up lie about the specs?

I wouldn't say they lied so much as they obfuscated the truth; the machine supported millions of colors, and with dithering techniques the monitor could look like it was displaying quite a lot of colors, but only the 20" display could display millions of colors without dithering (which was just like basically every other TN-based machine and display of the time)

Thank you for the clarification.

You do with temporal dithering

Was going to post this too. It was a popular technique for getting ‘more colors’ out of lower bit depth panels.

Weirdly hard to find out with a web search if his was done on the iMac G4 (your comment is already one of the top results for me on Google and DDG!).

Thousands and “millions of colors” in the control panel came from the CRT days. Guess they didn’t have the heart to reduce that just because the display device didn’t fully support it.

It's the difference between 16 bits per pixel and 32 bits per pixel in VRAM.

A screen using 18 bits per pixel (6 bits per color) would need the 'millions of colors' mode unless Apple designed some clever hack.