[TYPO3-ttnews] relations media if png stays png after process

[Jaco Graaff]

I would rather want all attached Media Element Files to convert to a jpg 
and not stay as type png if scaled

e.g.

<f:if condition="{mediaElement.type} == 0">
    <f:image
         src="uploads/tx_new/{mediaElement.image}"
         title="{mediaElement.title}"
         alt="{mediaElement.alt}"
         width="600c" height="320c" />
</f:if>

If I attach a *.png file it gets processed as a png file and a jpg as a 
jpeg - how can I enforce png to jpg if the user uploaded a png

Is this something I have to enforce in TypoScript or can I enforce it in 
Fluid

Thanks