No parsing of transparent background for PNG images

[wleoncio]

Summary

PNG images with transparent backgrounds are rendered with white backgrounds

MRE

---
marp: true
---

<!--
	backgroundColor: blue
	color : white
-->

# Testing image

![w:500](http://www.pngall.com/wp-content/uploads/2016/04/Plum-Free-PNG-Image.png)

Expected result

Something like this (sans sloppy paintjob)

Obtained result

[wleoncio]

I just noticed that passing the image as a background makes Marp properly parse the background:

So maybe there's a workaround to make this also work for non-bg images, or maybe to position the bg image so it's properly placed (e.g. as a header, footer, or next to text).

[yhatt]

Try to tweak the style of img elements.

<style>
img {
  background-color: transparent;
}
</style>

Marp Core default theme is depending on GitHub's Markdown style, and its style for <img> tag has white background color.

[wleoncio]

That's all it took, thank you very much!

BTW, I actually find it convenient that the default theme is tied to GitHub's Markdown style (however featureless it is), but as someone with very rudimentary CSS skills, I wish this specific tip was part of the Marp documentation (I couldn't find it anywhere).

Cheers \o

[yhatt]

Thanks! I'll give your feedback to working unified documentation.