A&D's Guides

Vertigo321 · Post by **Vertigo321** » Fri Jan 30, 2004 3:09 pm

I've started to update the colorspace portion of the A&D's guide. It's quite the task. Is anyone else interested in helping on this project, i.e. giving back to the anime community in general.

Topics:
Color
Color Spaces
Pixel Formats
How the pixel format chosen affect the end resolution.
Color space conversions: what they are/ how to avoid/ why they are bad

Vertigo321 · Post by **Vertigo321** » Fri Jan 30, 2004 3:20 pm

Upon finishing we will submit it back to AD or Ermac and perhaps they will adopt it either for the current guide or the second itteration.

Http://www.ucs.umn.edu/management/www/ip/Colorspace.htm
This is what I currently have. I'm thinking of cutting off the whole color portion because it really is superfluous from a practical point of view.

Let me know what your thoughts on this are.

trythil · Post by **trythil** » Fri Jan 30, 2004 3:41 pm

Actually, I like the portion about just what a colorspace is and why they're used.

Some points for correction:
YUV should be Y'CbCr, not Y'CrCb. (Well, I guess it could work either way from a programmer's standpoint, but everything I've read does it chroma red component first.)

You switch from describing linear luma to nonlinear luma when you get into Y'CbCr, but don't really describe why you made the switch -- that should be explained.

Speaking of YUV/Y'CbCr -- I'd standardize the entire section on one notation, or alternatively explain why you switch between them. Y'CbCr is not the same thing as Y'UV; this should be made clear (despite the fact that they're practically used interchangably...yeah, I've made that mistake several times.)

trythil · Post by **trythil** » Fri Jan 30, 2004 3:43 pm

trythil wrote:Actually, I like the portion about just what a colorspace is and why they're used.

Some points for correction:
YUV should be Y'CbCr, not Y'CrCb. (Well, I guess it could work either way from a programmer's standpoint, but everything I've read does it chroma red component first.)

...BLUE. BLUE.

b is BLUE. r is RED. Argh.

Vertigo321 · Post by **Vertigo321** » Fri Jan 30, 2004 4:03 pm

Hmm I wonder if calling it Y'CrCb or Y'CbCr really makes that much of a difference. They really don't specify byte ordering at this point... I'll make the correction though

AbsoluteDestiny · Post by **AbsoluteDestiny** » Sat Jan 31, 2004 6:50 pm

I appreciate the help but in all fairness... it's too detailed.

The aim of the guide is to have accuracy and usefulness... some of the additions although accurate are not particularly useful.

Feel free to make the additions you like but I can't guarantee that they will be included. Information is added based upon how useful it is to the member of this site - this guide, however useful it may be to the rest of the internet, is purely aimed at amv creators. We want to teach them the basics. I don't think rods and cones and absorbtion peaks fall into that.

Don't get me wrong, I find this interesting but it's really extraneous to the users of this site.

Guide updates are being made presently but they are focusing more on including infomation about YV12 and correcting the occasional mistake in the current version. This part of the guide is already quite obscure for most moembers - I'd rather make it easier to understand the concepts than to give them too much information that they don't need.

Vertigo321 · Post by **Vertigo321** » Sun Feb 01, 2004 4:36 pm

Some of the extra details could be included as "side treks" for those who wish to take the initiative and leave the noob relm. I agree with what you are saying, but at the same time I hate leaving people with just a thin veneer of information.

Vertigo321 · Post by **Vertigo321** » Sun Feb 01, 2004 4:48 pm

Perhaps I am going about this the wrong way. I should be asking, what is needed?

YV12 diagrams?
YUV subsampling diagrams?

I'm assuming most members can handle pictures

Maybe

Hopefully