Antialias problem

**deadline_coma** · 27 June 2006, 01:13 AM

I am new to Xara Xtreme. I would like to make web graphics and I need sharp, crisp edges with no antialias on rectangular objects. I set the grid to 1 px so objects will snap and I check the Info Bar to make sure object dimensions are in whole pixels and no decimals. I also make sure the stroke is set to "none" and when I export to BMP (true color), I get antialiased edges on a rectangle.

Can anyone shed some light on this?

TIA

**Egg Bramhill** · 27 June 2006, 04:08 AM

Coma,

It's difficult to say what's causing this problem without the original xar file. I suspect you could be checking the width and height are integer numbers, but perhaps the x and y positions aren't. If you have several objects this x / y positioning can cause the antialiasing your experiencing. It might also be a problem with bmp exports. Not sure, but it's a file type I rarely use and it's no good for web graphics.

Perhaps you could attach the problem xar file so we can try to reproduce the fault.

**deadline_coma** · 27 June 2006, 01:13 PM

Thank you for your reply. I have attached some files. The file that produced the antialias problem is test4.xar. It has some other nonsense objects in it. The exported bmp is test4.bmp. I just tried another test today and when I delete all other objects except a white background rectangle and save it as fuzzytest.xar, then export as fuzzytest.bmp, the problem disappears.

For some resaon it was unable to tolerate the existence of the other objects in the composition.

BTW, I did check the x and y coordinates to make sure they were integer values as well.

**gwpriester** · 27 June 2006, 01:34 PM

First of all, some anti-aliasing is necessary to smooth round edges and to make text look sharper.

If you move the Set View Quality slider to Normal (or Window > Quality > Normal) and look at your image it will look rather ragged, especially text.

But as Egg has pointed out, because Xara does anti-alias, your image needs to be in even pixels and aligned on the page to an even pixel amount. This will eliminate the intermediate colored pixels that Xara adds when an image is not in even pixel amounts.

Gary

**Charles Moir** · 27 June 2006, 02:17 PM

Sometimes there are very slight rounding errors that cause even images that appear to be whole pixel, to be very, very slightly more than a pixel, and that's enough to create the extra pixel in the export.

However if you use the 'Minimise visible anti-aliasing' option in the Export dialog, it does just that and should move things to be on exact pixel boundaries. And trying this on your design I get pin-sharp, no anti-aliasing results either exporting the white background rectangle or just exporting the red top rectangle. So I think that's what you're after.

**Egg Bramhill** · 27 June 2006, 02:33 PM

Your problem is being created due to some of your shapes not being whole pixel demensions and positions. Whilst the two rectangluar shapes are whole values the other objects aren't.

So if you select all the shapes (apart from the 800 x 600 white rectangle in the back) you will see the decimal place values. On export to gif you will get the ghosting around the rectangle shapes you showed in your first post.

If you just select the 2 rectangular shapes and export to gif there will be no ghosting, just clean shapes.

One further tip is to export 'Minimise Visible Antialiasing' selected under the 'Bitmap Size' tab. (Charles beat me to this one!)

**gwpriester** · 27 June 2006, 03:26 PM

However if you use the 'Minimise visible anti-aliasing' option in the Export dialog, it does just that and should move things to be on exact pixel boundaries. And trying this on your design I get pin-sharp, no anti-aliasing results either exporting the white background rectangle or just exporting the red top rectangle. So I think that's what you're after.

Great tip.

Gary