Image transparency not honored in PDF

[MCPBecker]

I found an old topic saying that transparent backgrounds for images don't work in PDFs. This still seems to be the case in Flare 10. Hasn't this been fixed?

[Dave Lee]

What images are you using?

PNG images with transparent backgrounds work fine for me in PDFs, using Flare v9.

[Helga WHigg]

I'm experiencing this as well in v9. I stumbled onto a blog that mentioned setting style backgrounds to "transparent," but nothing is working for me.

[Dave Lee]

Does the image actually include transparency?
Only certain image types support transparency (PNG, GIF), and the image must be saved with this transparency information.
If an image doesn't include transparency, you need to edit the image file itself to set it.

Setting a background colour to 'transparent' in your stylesheet (CSS) will have no effect on an image; that only affects the image tag/container, not the image itself.

[asmith]

My workaround for v9 had been to not edit the transparent image in Flare at all. I just resized the image outside of Flare to be the exact size I need, then imported it into Flare as usual. Editing transparent images in Flare doesn't affect the web-based outputs, just the printed ones. Guess this is still a bug in v10? I've not had to deal much with transparent images in this version, but my imported transparent images from v9 have held up so far using this workaround.

[ajturnersurrey]

This still seems to be a problem in v11!

Wierdly in my case image transparency for .png files is honoured in the topic preview, but not when the pdf target is built.

Anyone aware of any steps to get around this - I just want to get what I see in preview when I actually build the pdf!

Correct - Topic preview

correct.png

Incorrect - Built pdf target

incorrect.png

Can anyone suggest how I might correct this.

[ajturnersurrey]

Nothing like posting a request for help to ensure you figure out the answer yourself -
Setting image compression to automatic rather than jpeg did the trick!

[kirinawust]

THANK YOU! I was searching for this for ages!

[Jeong]

In case the internet is wondering about this, it's still a problem in 2022, and the option to set Image Compression to "automatic" in the target PDF Options does not work.

The issue for me is MadCap Capture (v. 7 is the latest in 2022). If the image has a Capture profile associated with it (you'll see a <filename>.<ext>.props file along with the image if you browse to it with File/Windows Explorer), then the background becomes white. If I remove the Capture profile and delete the corresponding .props file, then it renders as transparent.

I believe this is related to the Capture bug where if you drag a text callout bubble with a transparent background outside the image boundaries, the text is rendered bold.

Although it's frightening to have bugs live this long, they don't appear to have evolved any kind of individual or hive intelligence, so I don't think they pose a threat to humanity.