color calibration using curves (.acv files )

Do you know if there is a known procedure to calibrate the colors using a color target chart, the curves command and then save the results of the curves adjustment to apply afterwards to a real picture.
I know there are procedures to generate icm profiles but I want to avoid to buy expensive harware/software.
I am asking that, because even when using a custom white balance when shooting with my G3 camera, I am not very happy with the accuracy of colors I get.
Regards
Jose

GalaxyGauge.com has a inexpensive tool for that: Pixel Wrench Digital Photo Tool.

Thanks a lot for the link Franck.
I definitely must buy a color chart.
Best Regards
Jose