So, I have the following structure:
.
..
a.png
b.png
c.png
I ran a command to resize them
ls | xargs -I xx convert xx -res
Coming late to the party, but here's how you can rename files with xargs. Say you have a bunch of files named fileN.svg.png and you want to name them fileN.png where N could be a series of integers:
ls *.svg.png | xargs basename -s .svg.png | xargs -I {} mv {}.svg.png {}.png
The first xargs uses basename to strip off both .svg and .png to get a just filenameN. The second xargs receives that bare name and uses replacement to rename the file.