Alpha problem on slice export

**MerryOtter** · 01 December 2005, 05:55 AM

Hi Tim,

Here's a Xara Xtreme file for you to look at...

Rounded rectangle with slices defined at the corners. Seems to work ok vis a vis transparency. I did it a little differently than you did, however.

When I tried to work with your file, the transparency worked correctly as well. Perhaps it's because I'm using the Nov 23 version of Xara Xtreme?

Merry

**timdw** · 01 December 2005, 09:11 AM

Thanks Merry - that one doesn't work for me either

I am using the Nov 23 version too. I think it's time for a support request. I'll just post my system specs here in case it helps (I'll be giving a link to this thread in the support ticket):
Windows XP SP2 (regular 32 bit version)
AMD Athlon 64 X2 3800+
1024Mb Ram
256Mb Geforce 7800GT
Gigabyte GA-K8NXP-SLI Motherboard

I'll post back here if I get a result,

Tim

**MerryOtter** · 01 December 2005, 02:10 PM

Tim,

My only other thought is... have you tried to disable the external plugins folders yet?

(Utilities--> Options--> Effects & Plugins --> Setup...)

I suggest this because a long time ago, I had Paint Shop Pro configured to look at a folder of plugins and it somehow picked up some file filters that really messed with the JPG and GIF output. (Even if those filters weren't used.) Perhaps a similar situation with your copy of Xara?

**timdw** · 01 December 2005, 03:48 PM

Afraid not, there's nothing in there. I'm racking my brains trying to think what it could be. Maybe the Athlon 64 processor? I'm sure someone else would have noticed by now though if that were the case.

*Edit* Installed on my laptop which has a Pentium 4M, no change.

**Egg Bramhill** · 01 December 2005, 07:57 PM

Tim

I'm not 100% sure what your after but I think the attachment may help.

Let me know.

Egg

**timdw** · 01 December 2005, 09:14 PM

Much to my surprise that works perfectly! I'm just trying to figure out what I'm doing wrong and I'll report back presently.

Thanks Egg

**timdw** · 02 December 2005, 12:22 AM

Right, I think I've got it! While setting up my slices I've been using the export tool from the name gallery to preview the results. This is in fact a bad idea as to see anything you have to set the "Make background Transparent" button to off. This setting is also used by the slice tool hence the no-transparency slices. I have to admit that I thought that the export and slice were basically the same thing, with the slice being a convenient method of batch exporting named areas into a table. They are not the same at all. The export function treats transparency completely differently, coming at things from the exported bitmaps point of view, here's what the help file says:

"Transparent background: dimmed for BMP format and PNG True Color. Make transparent any areas not covered by the selected objects. Selecting this option automatically makes one entry in the palette transparent. Transparent on the Options tab duplicates this button."

This seems pretty straightforward, but what it really means is if the object is transparent, and you select this option, the bitmap will be entirely transparent! If you de-select, the stuff behind on the page will show through but there will be no transparency at all, unless you manually assign a transparent colour, which doesn't show in the preview but does work when exported.

I think the root of my confusion is the fact that the page background is not, and can not (correct me if I'm wrong, I hope I am!) be transparent. If it could be the export function would work the way I expected. Perhaps I should say the way I'd like it to

As an aside, don't use an exported 24 bit PNG with alpha for web graphics without going here for a javascript fix for IE. By default, IE can only handle on or off for transparency in PNGs and Xtreme appears to use the alpha channel for anti aliasing when exporting them.

Thank you everyone for all your help with this, I can only hope that my mistakes can help someone else so that this hasn't been a complete waste of time.

Tim

**Egg Bramhill** · 02 December 2005, 05:17 AM

I'm not sure if this helps. You'll definitely need a broadband connection.

www.xlwebdesign.co.uk/fun/avi/1.avi

I'll try to keep the file size down next time.

(You can see where that sexy female British voice comes from now!)

Egg

**timdw** · 02 December 2005, 12:19 PM

The sound of a real Essex girl

That is helpful, I think I understand how it works now. Things is, after reading about slicing I thought Aha! If I do a mock up of the site I'll be able to quickly see what it looks like in a browser, if I don't like it I can just go back, tweak and re-slice. When doing this though there's extra junk slices produced which I don't want (fluid layout using background colours & repeat images for stretchy areas), so I thought "Hmm, save a bit of time and just use export instead, it's doing the same thing" which is when it all went pear shaped and the slicing stopped doing it's thing too. Thinking about it, I can do what I want if I'm not so obsessive about getting the absolutely smallest slivers of images I can get away with and just use what comes out after slicing normally.

Thanks again,

Tim

**MerryOtter** · 02 December 2005, 02:29 PM

Originally Posted by Egg Bramhill

I'll try to keep the file size down next time. (You can see where that sexy female British voice comes from now!)

Attached is a much more digestable WMV. Only 7% of the original file size (8.5 MB down to 625K). Very easy to compress with Windows Media Encoder. The "tutorial" on this is at http://www.talkgraphics.com/showthread.php?t=19057

(I didn't know that Xara had employed Bugs Bunny for the tutorials)