FileUpload alters png colormodel.transparency from OPAQUE to TRANSLUCENT


We’re using FileUpload in our images upload, and finding that some pngs will come out looking like an orangish-red-colored photo-negative.

I have examined the photo EXIF metadata before upload and after.

Difference which I believe is causing this is:

  • original photo has colormodel.transparency=OPAQUE
  • uploaded temp photo has colormodel.transparency=TRANSPARENT

I also see this diff but not sure if it’s related:

  • original photo has colormodel.pixel_size=24
  • original photo has colormodel.pixel_size=32

There is also some other EXIF metadata that Lucee seems to strip.

I cannot see any configuration on why this get changed, nor any functions to set it manually.

Any ideas how we can fix this so our png uploads work?

OS: Windows 10 and Server 2012
Java: 1.8.0_351
Tomcat 8.5

I checked this issue and unable to replicate this issue and could not see any difference in the colormodel transparency and pixel_size values.
@taivo So, can you please provide any other details to replicate this issue?

1 Like

Hi @cfmitrah,
I was prepping a response when the decision was made to drop png support here. Webp is the future!
Really appreciate you checking, but I’ll close this as my investigation is now ended.