Generate barcodes with a specified "module size"

[rominator1983]

I am building a product that has document output management functionality.

At the moment we are using a commercial library for generating barcodes. It supports generating barcodes with a fixed module size. That is the generated image has a controllable number of pixels for every white or black square of barcode information. This holds true for 2d or linear barcodes and must of course match with the wide/narrow ratio of a linear barcode.
Thus we can guarantee a specified number of modules per inch. This is required by scanners of returned correspondences that scan barcodes that are printed on paper.

We tried to achieve something similar with zxing and did not find out how/if this could be done. Would I have to make adjustments to the source to be able to do this?
It was only possible for us to generate images with an unknown or unspecified module size.