Image looking low res after export to PDF

[defaultjgulttbtvevk]

Hi there,

I'm working on something for a client who has this image they created in keynote but now what to adapt it for print.
The image is 1920x1080 px but they want to scale it down to about 50mm. 

So, when I do this in InDesign, everything looks nice & clear – but when I export a PDF, this particular image is very blurry.
I tried to edit the size of the image in Photoshop but still the same result.

I think it's just not going to work because of how they produced the image, but maybe I'm missing something? 

Thanks for any tips!

[Eugene Tyson · Accepted solution]

Can you increase the resolution in the compression section of the PDF export?

Firstly check the resolution on the image in the links panel and see if the effective resolution is high enough.

If not you can offer to recreate it, whether you charge for this or not it's up to you.

[defaultjgulttbtvevk]

Thank you so much!
It was caused by the compression setting (it was downsampling images over 450ppi to 300ppi, this image was 1000ppi)