Is it possible to implement to rezise function from ConvIm to ConvImX? would like to resize a whole bunch of textures without loosing the alphachannel.
Possible.... but not easy
As you have guessed you can`t just do a simple resize. The image and alpha need to be seperated, both resized and then joined back together again.
I will have a look at it but it may not be possible without major rewriting. ConvImX was just intended as a simple tool for the mass conversion of textures between different formats rather than something for modifying existing textures