Variation in exported image size based on coordinate position when using Asset Export

[cgbrown-mos]

I think I'm seeing a bug in the size of an exported image when using Asset Export for Illustrator v27.5 (did not test or use this feature previously in any other versions). Here's what I've done and the result I'm seeing:

• Create a new empty document, I used an artboard size of 60" x 36" with coordinates (0", 0")
• Add a square to Layer 1 sized to 5" x 5" with a position of (10", 10")
• Create a new layer, Layer 2
• Add another square to Layer 2 sized to 5" x 5" with a position of (30.5", 20.5")
• Select Layer 1 and Layer 2 in the Layers menu
• Then select Collect for Export
• In Asset Export, change the export settings to scale to a resolution of 25 ppi as PNG
• Then export

What do you think happens? I had expected 2 images each with dimensions of 125 x 125. BUT instead I get one image at 125 x 125 and the other image at 126 x 126.

This seems like a bug where the export is rasrterized based on the artboard coordinates instead of relative coordinate, which can result in fractional dimensions that round up. Has anyone else noticed this? Is there anything that can be done about it?

Thanks!

Chris

[Anubhav M]

Hello @cgbrown-mos,

We understand that encountering technical issues can be frustrating. Would you mind trying the suggestions shared in this community post (https://adobe.ly/3UZKO9o) and checking if it helps?

Looking forward to hearing from you.

Thanks,
Anubhav

[cgbrown-mos]

Hi Anubhav,

I saw that post last night and I'm certain now that this is a bug. The users in that thread came up with mitigation strategies (which don't resolve all my issues), but they are ultimately rationalizing a 7+ year bug as user error. It's not user error, it is a bug. How can I get a bug report filed and reviewed?

Thanks!

Chris

[Monika Gause]

You have to create your artboard and the artwork in the pixel grid and then not resample when eporting. That's how Illustrator works. 

If you want to make a feature request, then please: https://illustrator.uservoice.com 

[Ton Frederiks]

Chris, as long as you use 72 ppi as output resolution and artboards and objects align to the pixel grid you will see no additional pixels.

Changing the output resolution to something other than a multiple of 72 ppi can generate additional anti-aliased pixels caused by rounding.

With your example of a 360 pixel sized object at 25 pixels per inch you would expect an image of 125 pixels (360/72 = 5 and 5X25 = 125).

You will get that when the upper left coordinates of the object can be divided by 72 and the result does not contain fractions. This happens with individual assets on a single artboard, as well as objects on multiple artboards.

I think that the behaviour of rounding fractional pixels can certainly be improved (I would prefer rounding down) but this explains what is happening.

[cgbrown-mos]

If anyone is coming across this post looking for a solution to asset or artboard exports being off by 1 pixel, Adobe is looking into the issue.

You can vote for a feature request to fix this issue here: 

https://illustrator.uservoice.com/forums/333657-illustrator-desktop-feature-requests/suggestions/309...

And you can vote for a bug fix to this issue here: 

https://illustrator.uservoice.com/forums/601447-illustrator-desktop-bugs/suggestions/48077885-variat...