Reason: Transparent backgrounds use an alpha channel to become transparent

Already discussed here

Then should alpha channel just be done away with?

If we're going to get into semantics like that, we're going to start tagging images by file format, bits per pixel, number of animation frames...

GreyMaria said:
If we're going to get into semantics like that, we're going to start tagging images by file format, bits per pixel, number of animation frames...

Well things like file format, resolution, aspect ratio, etc. can be searched for without being tagged.

My issue is that alpha channel seems like something we can do without because it describes something internal to the image, or does it?

Rainbow_Slash said:
Well things like file format, resolution, aspect ratio, etc. can be searched for without being tagged.

My issue is that alpha channel seems like something we can do without because it describes something internal to the image, or does it?

I wouldn't call it any more internal to the image than any opaque color.

I would suggest, instead, that alpha_channel be aliased to "transparency", and for transparent_background to imply transparency... unless someone thinks that would seriously collide with the particular type of projector that goes by the same name. This would unify alpha_channel and transparent_background into something that is definitely a component of the picture without getting into technical details about how it got there.

Edit: It turns out there is exactly one image with the tag "transparency", and it has nothing to do with machinery.

post #206634 for those Final Fantasy fans out there that are interested in Nu Mou pr0n.

ikdind said:
I wouldn't call it any more internal to the image than any opaque color.

I would suggest, instead, that alpha_channel be aliased to "transparency", and for transparent_background to imply transparency... unless someone thinks that would seriously collide with the particular type of projector that goes by the same name. This would unify alpha_channel and transparent_background into something that is definitely a component of the picture without getting into technical details about how it got there.

Edit: It turns out there is exactly one image with the tag "transparency", and it has nothing to do with machinery.

post #206634 for those Final Fantasy fans out there that are interested in Nu Mou pr0n.

I agree with this. It seems as though alpha channel is more process than product and transparency is a good middle ground

The way alpha channel is encoded is totally irrelevant. When picture is saved as a GIF file, alpha channel is represented by a single byte. When picture is in computer memory, its representation can be totally different, native encoding in memory can be 32 bit with true alpha channel.

It's encoding. Compression technique for 1-bit alpha channels.

No one really cares how alpha channel is encoded in the file. If I search for transparent background or alpha channel, I expect the file to have transparent parts and that's it.

How can a difference between current “transparent background” and “alpha channel” be used? To distinguish between GIF and PNG? May be useful, but totally non-obvious, so useless. To distinguish between 1-bit alpha channel and 8-bit, between quality that is? True alpha channel can also be equivalent to 1-bit if it only contains values 0 and 255. So it is useless too.

As it currently is, the tags only cause confusion.

You may introduce a third tag, to cause even more confusion. But it will only solve the problem YOU have invented.

FeralBeast said:
"words"

Rainbow_Slash said:
Then should alpha channel just be done away with?

I dont think you read some of the comments. Like I said, its more process than product. I think it should be aliased to transparency and done away with.

Requesting Alias: alpha_channel-->transparency
Requesting Implication: transparent_background-->transparency

Or something similar given transparent is alias to translucent and that's not for the background

I prefer the alpha_channel tag over transparency though, alpha_channel clearly refers to an image having transparent areas, but transparency could mean that, or something in the image itself being transparent (like thin cloth or glass), plus I've just always liked the sound of alpha_channel.

I do think that 1-bit GIF transparency and 8-bit PNG transparency should share the same tag though.

transparent_background - things are overlaid on a transparent plane
alpha_channel - image using GIF 1-bit or PNG 8-bit transparency.

So transparent_background should imply alpha_channel

Adrian_Blazevic said:
transparent_background - things are overlaid on a transparent plane
alpha_channel - image using GIF 1-bit or PNG 8-bit transparency.

So transparent_background should imply alpha_channel

there are images (gifs, for example) that have transparent backgrounds that do not utilize the alpha channel effect.

GreyMaria said:
If we're going to get into semantics like that, we're going to start tagging images by file format, bits per pixel, number of animation frames...

tags:
animated
gif

bmp

jpg

png
tiff

tony311 said:
I prefer the alpha_channel tag over transparency though, alpha_channel clearly refers to an image having transparent areas, but transparency could mean that, or something in the image itself being transparent (like thin cloth or glass), plus I've just always liked the sound of alpha_channel.

I do think that 1-bit GIF transparency and 8-bit PNG transparency should share the same tag though.

Well for things in the image actually being transparent, the tag translucent is being used. So I think we either keep alpha_channel referring to a transparent element and ignore if it really utilizes such technique or we alias it to transparency and use translucent for things being see-through in the image

If tagging is for searching, would anyone ever actually search for alpha_channel? Not that I think too many people search for transparent_background, either, but it does seem more likely, at least.

To me, an alpha_channel tag just seems a little over-the-top and not really necessary.

DobiesHot said:
If tagging is for searching, would anyone ever actually search for alpha_channel? Not that I think too many people search for transparent_background, either, but it does seem more likely, at least.

To me, an alpha_channel tag just seems a little over-the-top and not really necessary.

Yes, we should just alias it to transparency and use transparent for the image elements and use translucent for "see-through" things in the image.

This topic has been reemerging for too long now and it seems we need a better solution than leaving as is

alpha_channel and transparent_background are fine as they are

ippiki_ookami said:
alpha_channel and transparent_background are fine as they are

So then should it be added to every image using a transparent background?

Rainbow_Slash said:
So then should it be added to every image using a transparent background?

not the ones I mentioned earlier

ippiki_ookami said:
not the ones I mentioned earlier

noted, updating wiki

I dunno. Transparent_background seems to work really well, and it falls in line with the other background tags—(color)_background, simple_background, plain_background, etc.

I guess I just don't understand why everyone is so picky about this one. I think people are making it more complicated than it has to be.

DobiesHot said:
If tagging is for searching, would anyone ever actually search for alpha_channel?

Yes, we do. I have, at least. transparent_background too.