How to convert pictures to TDX format ?

I can't find a place that explains how to convert cards art to TDX format.
Do you use the Gibbed TdxConvert tool ? When i try, it gives me a size file of 500k instead of the normal 126k size that i can find in the illustrations archive...
I've tried to see at options (like --dxt1) for TdxConvert.exe using command line but it seems there's none.
How do you convert all the images then ?
Do you use the Gibbed TdxConvert tool ? When i try, it gives me a size file of 500k instead of the normal 126k size that i can find in the illustrations archive...
I've tried to see at options (like --dxt1) for TdxConvert.exe using command line but it seems there's none.
How do you convert all the images then ?