32-bit color

[JeremyLangford]

I am confused about the bit depth of my 13" unibody macbook's built in LCD monitor. If I look at the specs in "About This Mac", it says that my screen has 32-bit color.

The only 32-bit color that I'm familiar with consists of 8 bits per pixel and an extra 8 bits for the "alpha channel". But the alpha channel represents transparency which is handled by the video card and never sent to the monitor right? Why would my monitor be 32-bit if it only needs 8 bits per pixel to determine the color of a pixel?

After trying to figure this out, I was told that my monitor has a TN panel which means that it is actually only 18-bit with 6 pits per pixel.

What is true?

 

[spinnerlys]

http://discussions.apple.com/thread.jspa?threadID=2068556&tstart=0

via http://www.google.com/search?hl=en&...h+of+tn+display+macbook+pro+led&aq=f&aqi=&oq=

 

[sammich]

http://en.wikipedia.org/wiki/Truecolor

8 bits per colour (red, green blue), 8 bits for alpha

 

[JeremyLangford]

I'm not worried about whether my screen is 6-bit or 8-bit. What I don't understand is why "About This Mac" says that my screen is "32-bit". 32-bit means that there are 8 bits per pixel as well as an extra 8 bits for the "alpha channel" but as far as I know, the alpha channel represents transparency which is handled by the video card and never sent to the monitor. What exactly is meant by the 32-bit spec?

 

[spinnerlys]

Have you read the answer above your post?

Does that bring some clarity? http://www.tftdisplay.org/

 

[JeremyLangford]

Yes, I've read all tha answers and I don't understand why "About This Mac" tells me my monitor has 32-bit color.

 

[spinnerlys]

But you can't seem to use a web search engine.

http://www.google.com/search?client=safari&rls=en&q=tn+display+32+bit&ie=UTF-8&oe=UTF-8

Color Depth - Most consumer panels are TN types with 6 bit color. 3 dots x 6 bits = 18 bit color. Look at your machines display settings .... if the number is 24 or bigger, the number between 18 and that number is "dithered". Note 32 bit color is not really 32 bit, it's 24 bit color with 8 bits of "non color data".
from http://www.tomshardware.co.uk/forum/249000-15-what-extra-8800gt

to this http://en.wikipedia.org/wiki/Color_depth#8-bit_direct_color
or this http://apple.slashdot.org/article.pl?sid=07/05/23/1224253

The copy and pasting took more time than the search.

 

[JeremyLangford]

Thank you. I have done a lot of searching but I never found this quote.

"Color Depth - Most consumer panels are TN types with 6 bit color. 3 dots x 6 bits = 18 bit color. Look at your machines display settings .... if the number is 24 or bigger, the number between 18 and that number is "dithered". Note 32 bit color is not really 32 bit, it's 24 bit color with 8 bits of "non color data"."

That helps a lot.