Slicer Question

[lau3]

Xara allows you to create sub-pixel sized images , i.e., 11.23 pixels wide. However, export to GIF are in whole pixel increments. That is, there is round off.

If you have ever exported manually sliced images and put them together in a web editor, you will find that if your slice regions are not in whole pixel sizes, you may loose some info in the edges of the images.

Does the slicer in XaraX take care of this problem so recomposing a sliced image does not lose anything?

Thanks,

Milt [img]/infopop/emoticons/icon_biggrin.gif[/img]

[diniel]

Though this doesn't always solve everything, it frequently at least improves the export:

Before you slice your image, clone it. (Select your image and press CTRL+K) This puts an exact copy of the selected object directly above the original.

Now work on slicing up the cloned object, keeping the original beneath. Having the original behind so Xara can "see through" the gaps where you sliced when you export often improves the export - if only because the exported item's edge is anti-aliased to the missing pixel, even if the actual missing pixel isn't there.

Daniel

[gwpriester]

Milt

To be honest, I have not tested this to see how Xara handles fractional pixel images.

The easy solution, however, is to work in Pixels, and enable snap to grid and make sure that all your slices are in even pixel amounts.

Xara handles fractional pixel amounts by antialiasing the fractional pixles which is not all that visually attractive :-)

Gary

Gary Priester

Moderator Person

Be It Every So Humble...

[Sean Sedwards]

Milt

I assume that you're talking about slicing up bitmaps, but in case you mean slicing up the vector drawing first - don't!

A number of people have reported trouble with this, however I find it seamless (literally). My technique is as follows:

1. Convert the drawing to a single bitmap using your chosen dithering and palette,

2. Set the quality to 'Normal',

3. Slice up the drawing using horizontal and vertical lines and Arrange > Combine Shapes > Slice (cut) Shapes,

4. Export each piece with the same dpi and palette as the original.

Explanation:
1. The first conversion defines how the assembled bitmap will look.

2. Setting the quality to normal prevents Xara from anti-aliasing the edges.

3. Because of the way Xara's bitmap sampling algorithm works, horizontal and vertical lines guarantee that what is lost from one piece will appear in the next. The pieces may have fractional screen dimensions, but this in itself will not result in any losses.

4. The sampling algorithm works most reliably when it doesn't have to do any resizing, so keep the same dpi throughout. You've already done the dithering, so just keeping the same palette will ensure that each new bitmap copy is identical to the original.

Regards - Sean