Bevel inaccur... erm, weirdness... ;)

[Egg Bramhill]

Cheers Miguel.
I can understand this bit now, but I still can't grasp Eobets original problem. (Must be me being really thick today!)
Egg

[John Rayner]

Hi Eobets,

okay... how about decreasing the antialiasing a click, and do not use dithering of the colors on the gif?

[eobet]

Ok, AndFarr and Miguel needs to re-read my original posts again, because you totally disregarded what I said in them. http://www.talkgraphics.com/images/smilies/tongue.gif

John Rayner had a good tip, though, but Xara responded even worse to it, unfortunately (I hope the picture also removes all doubts about how I created the image)...

http://www.eobet.com/temp/xara2.jpg

[MEB]

Sorry eobet i misunderstood your question.
Regarding the dirty/mess look of the icon inside Xara at 100% for small images compared to what a resized image would look the reason for those diferences is what i said in my first post(I saw for your screengrab of Xara that you are already using full units and positioning).

This is because the anti-aliasing tries to smooth the objects. For vertical and horizontal lines there´s no problems, but for rounded areas or other lines angles it just "blurs" the vectors and as a result the image will look less sharper.

The second reason has to do with how vectors will translate in to pixels when displaing images on screen or when exporting them. Sometimes our vector object(s) doesn´t fit precisely in a rigid grid of pixels, resulting in some strange "artifacts" like lines appearing bolder than others even if their line width is the same. Always make sure you´re using "full units" (like 4 pixels line width and NOT 3.5px) and use a grid or check the XY position of the object to position your objects precisely.

Those inconsistencies are visible at diferent zoom levels because Xara has to "rescale" how your vectors will fit in a rigid grid of pixels (that is your screen).
So it´s normal that they change a little in appearence when seeing them at a diferent zoom levels.

But from my experience there´s nothing more you can do about it to improve the quality of small images at 100%, like a 16x16 icon inside Xara X because of the anti-aliase feature. And as you already saw reducing or turning the anti-aliase off doesn´t help.


So i sugested that you create the icon at a bigger size in Xara and then resize/downsample it in photoshop (seems you already done it) or create it in Photoshop from scratch since photoshop is more adequate for pixel work.


As far as i know there´s no way to get a clear "rendering" of a vector image at those small sizes in Xara.

Miguel

[eobet]

Right, but that must surely be a bug, since at larger zoom it has the correct (brighter) color, and shrinking it in Photoshop prooves that it should be able to contain a lot more detail than what Xara manages.

Anyway, I had to manually remove all the aliasing in the resized image, but I went with it.

It wasn't an important image anyway, but raises an important topic to me:

I would really like to be able to convert the bevels into objects, similar to what you can do with contours.

[Egg Bramhill]

Eobet
If you place your bevel into a 16 x 16 grid you can see how difficult it is for the computer to know which pixel to colour for which underlying shape.
Try changing your screen display under Options / view to Error Diffused. Don't know if this helps or not.

http://www.xlwebdesign.co.uk/tg/antialias.gif

Egg

[MEB]

There´s another thing you can try that teoricaly should improve the result but i didn´t tested it yet in my own work so i can´t grant any results.
Xara X has an even higher anti-aliase setting that isn´t enabled by default because it´s more heavy in resources. There´s no way to activate it trought the Xara settings. You have to download this (great) utility developped by Dmitry
(aka Access in Xara forums) from his page X1 Tune.
There´s a setting named High Quality Render (see the screenshot in his page). Just check the box and restart Xara.
Note that this will change your registry settings.


Since the bevels in Xara are bitmap effects and not true vector objects there´s no way to convert them as you do with contours.
Hopefully Xara may correct that in a future version (i hope).

Regards,
Miguel B.

[eobet]

Originally posted by Egg Bramhill:
Eobet
If you place your bevel into a 16 x 16 grid you can see how difficult it is for the computer to know which pixel to colour for which underlying shape.

As I said, I work with integers when I create my icons, and I fit them better than your example, though still not perfect, I admit:

http://www.eobet.com/temp/xara3.jpg

Still, there is no way you can logically defend Xara in this case. Just look at the group of four icons I put to the right. You have already seen the bottom two and granted, Photoshop has bi-cubic resampling and that is probably not something Xara could have without becoming very slow. But look at the top two icons! They are done using NO anti-aliasing and nearest neighbor resampling (the PS eqvivalent) and still the Xara renders it garbled, while PS prooves that there is ample room for a more correct display.

Originally posted by Egg Bramhill:
Try changing your screen display under Options / view to Error Diffused. Don't know if this helps or not.

Thanks for the tip! It didn't produce any better results, though.

Originally posted by Miguel B.:
There´s another thing you can try that teoricaly should improve the result but i didn´t tested it yet in my own work so i can´t grant any results.
Xara X has an even higher anti-aliase setting that isn´t enabled by default because it´s more heavy in resources. There´s no way to activate it trought the Xara settings. You have to download this (great) utility developped by Dmitry
(aka Access in Xara forums) from his page X1 Tune.
There´s a setting named High Quality Render (see the screenshot in his page). Just check the box and restart Xara.
Note that this will change your registry settings.

I'm not using X1, though, so I'm not sure I dare to use that program. I had a look in the registry, but the Xara entries are legion, so I wasn't sure what to change.

[Egg Bramhill]

Strange this Eobet. I can't reproduce the poor quality that your getting. I recreated the 'cog' from your posting above and created bitmaps using this recreation.

http://www.xlwebdesign.co.uk/tg/eobet.jpg

It could be a problem with your earlier version of Xara?

Egg

[eobet]

Well, X1 has by default a better anti-aliasing method than old Xara. Still, I think you reproduced it quite well (the darker color you got without reducing/enhancing shouldn't be there).

Anyway, the issue is now hopefully highlighted enough so that at least one developer has seen it (hopefully). http://www.talkgraphics.com/images/smilies/wink.gif