When looking at the broadcast details from the EPG Program Guide tab, both the channel logo, and an image for the program are shown.

I assume that both these images come from the guide data.

My guide data (from Schedules Direct) contains a single channel logo, but multiple icons, at different resolutions and aspect ratios, for each show.

Does TVheadend just use the first image it finds? Unfortunately, that is the one with the lowest resolution.

Here is a sample entry:

<programme start="20191231050000 -0500" stop="20191231053000 -0500" channel="I19.2.54702.schedulesdirect.org">
<title lang="en">Highway Patrol</title>
<sub-title lang="en">Dead Hunter</sub-title>
<desc lang="en">An apparent hunting accident may actually have been murder.</desc>
<credits>
<director>Herbert L. Strock</director>
<actor>Broderick Crawford</actor>
<writer>Lou Huston</writer>
<presenter>Art Gilmore</presenter>
<guest>Joe Haworth</guest>
<guest>Pierre Watkin</guest>
<guest>Voltaire Perkins</guest>
<guest>Ron Foster</guest>
<guest>Louise Smith</guest>
</credits>
<date>19571209</date>
<category lang="en">Crime drama</category>
<icon src="https://s3.amazonaws.com/schedulesdirect/assets/p8084629_b_v6_ab.jpg" width="120" height="180" />
<icon src="https://s3.amazonaws.com/schedulesdirect/assets/p8084629_b_v2_ab.jpg" width="135" height="180" />
<icon src="https://s3.amazonaws.com/schedulesdirect/assets/p8084629_b_h5_ab.jpg" width="180" height="135" />
<icon src="https://s3.amazonaws.com/schedulesdirect/assets/p8084629_b_h14_aa.jpg" width="240" height="135" />
<icon src="https://s3.amazonaws.com/schedulesdirect/assets/p8084629_b_v5_ab.jpg" width="240" height="360" />
<icon src="https://s3.amazonaws.com/schedulesdirect/assets/p8084629_b_v3_ab.jpg" width="270" height="360" />
<icon src="https://s3.amazonaws.com/schedulesdirect/assets/p8084629_b_h3_ab.jpg" width="360" height="270" />
<icon src="https://s3.amazonaws.com/schedulesdirect/assets/p8084629_b_h13_aa.jpg" width="480" height="270" />
<icon src="https://s3.amazonaws.com/schedulesdirect/assets/p8084629_b_h12_aa.jpg" width="960" height="540" />
<episode-num system="dd_progid">EP01255302.0055</episode-num>
<episode-num system="xmltv_ns">2.9/39.</episode-num>
<previously-shown start="19571209000000" />
<subtitles type="teletext" />
<rating system="USA Parental Rating">
<value>TVPG</value>
</rating>

</programme>

Since this same image is also what is displayed in the Kodi front-end, it would be nice to use the best resolution available.