are you talking cmpr tpls or what? if so, gxtexconv can make them. but i dont think it handles the alpha correctly when doing this format.

# convert to png:
wimgt dec SOURCEIMAGE --dest output.png
# convert to tpl/cmpr
wimgt enc SOURCE.png --dest output.tpl --transform tpl.cmpr
my szs tools support tpl/tex0/breft images with different image formats including cmpr and mipmaps/multimage support.
Code:# convert to png: wimgt dec SOURCEIMAGE --dest output.png # convert to tpl/cmpr wimgt enc SOURCE.png --dest output.tpl --transform tpl.cmpr
One issue: There are different tpl/tex/... sub formats and my tools only support the Mario Kart related formats.