Hello,

We are now required by law to digitalize all the financial documents in our company and submit them to evaluations every 3 months.

Since this is sensitive data we decided to take matters into our own hands and build some sort of digital data archiver. The tool works perfectly, but after 7 months of usage we are begining to worry about the disk space used by these images.

Here some info on the amount of documents digitalized:

• 15K documents scanned and archived per day, with final PNG size of +- 860KB: 15 000 * 860 kilobits = 1.53779984 gigabytes
• 30 days of work per month: 1.53779984 gigabytes * 30 = 46.1339952 gigabytes
• Expectation of disk space usage after 1 year: 46.1339952 gigabytes * 12 = 553.607942 gigabytes

So far we're at 424 gigabytes of disk space used, without counting backup. We're using PNG as image format, but I would like to know if anyone have any advice on a better compression algorithm for images or alternative strategies for compressing the PNG's even more or even better ways to archive images as to save disk space.

Any help would be appreciated, thanks.