Black background in JPG-export although having white background

[joe_l]

My testfile was a former v1-document in sRGB with rasterised images. When I now open the file in v2 and export to JPG, the white background turns black in the preview window as soon as I change a selected preset e.g. turning off ICC embedding and indeed the exported image has a black background now.

v1 exports fine, v2 document and screenshot are attached.

Bedeutung Patchkabelfarbe_exporttest.afpub

[NotMyFault]

The images have transparent background. Your file has no background at all.

When exporting to raster formats not supporting transparency like JPG, transparencies get flattened and matted: in Export UI, you can choose which color is used for transparent areas, probably “Hintergrund” in your screenshot. 
 

What happens if you click on the white color, and actively select one?
 

A better way is to simply add a rectangle in your preferred color on the master page as bottom layer.

Unintended transparencies can cause many surprising issues in PDF documents.

[joe_l]

4 minutes ago, NotMyFault said:

Unintended transparencies can cause many surprising issues in PDF documents.

Erm, the background of the page is NOT transparent (white) and why is the background turned into black even when unchecking embedding metadata? As you see on the screenshot, "Hintergrund" is already white. Funny thing is, that when I use the RGB sliders for background the background will not be updated to the new colour. Here I have use an other slider to see the backgroundcolour change.

[NotMyFault]

The background is transparent. You can see if you choose "PDF" as export format.

Then, if you switch to "JPG", there is a minor UI bug. The matting color is shown in white, but actually black is active.

You can correct this by re-selecting white as matting color.

 

So there is a UI bug: the preview of the matting color is wrong. Never the less, if you actively choose the matting color again, the preview gets updated, and export is correct.

[joe_l]

4 minutes ago, NotMyFault said:

The background is transparent. You can see if you choose "PDF" as export format.

Debatable I would say, that a non-transparent background is transparent no matter what option is checked resp. not checked.

[NotMyFault]

Never the less, as you can see in Export Preview, and if you open the file in Photo (channels panel), or use a channel mixer adjustment:

It shows a transparent background.

 

 

 

[NotMyFault]

The flag in Document Setup "transparent background" only impacts the rendering in Publisher, but does not affect the actual document data.

If set, Publisher will show the background as checkered board of light grey / white pixels.

If not set, Publisher will show a white background - which is misleading. The document still is transparent in certain areas!

To summarise:

• If you want to have a document without transparent areas, you need to add a opaque filled layer as bottom layer.
• The "Transparent background" in Document setup only impacts rendering in Publisher (not Export). I agree this is bad UI.
• At export to bitmap formats (e.g. JPG, PNG) you can choose to flatten the transparency and replace by a chosen matting color (completely unrelated to document setup)
• When exporting to formats supporting vector objects (e.g. PDF, SVG), transparencies stay unless you choose to activate "matting" during export.