Steps to reproduce

1. Upload a PNG to Assets app
2. Copy the UUID from JCR app
3. Go to a FTL file and generate an image link using a rendition like thumbnail

   <img src="${damfn.getAssetLink("jcr:b1858280-ad8d-44e9-9063-b76b3eb5658a", "thumbnail")}"/> 

4. Render the template and download the generated image
5. Check it size is , at least, 4 times bigger than the original (even its size is smaller)

Expected results

The image size is not dramatically increase

Actual results

The image size is much bigger than the original

Workaround

N/A

Development notes

It doesn't happen if the image format is JPG.
TEST 1:
PNG image size: 4kb
Size of the rendition: 232kb

TEST2:
JPG image size: 103kb
Size of the rendition: 41kb