I have a large quantity of mylar plats and drawings I need to scan and archive. We have a high quality large format scanner, but I'm wondering what settings and file format work the best - PDF, JPG, TIFF, etc.?ÿ I'm looking for the best quality image, without a giant file size.?ÿ Also, a format that would work well to link to a database, GIS, CAD, etc.
I've used both PDF and JPG (JPG2000).?ÿ
Image quality is good on both file types. Using a DPI of 300 you get a good quality and the file size isn't unmanageable.
The local county surveyor's Survey Records databases seem to favor .tiff. Most of them will convert to pdf on download, if desired. I think pdf is going to be more useful to non-technical users. Tiff may be a smaller file size for a given image quality.?ÿ?ÿ
My recommendation is to scan at the highest resolution available. You can always decimate the files later. Storage capacity is getting cheaper by the day.
I scan everything at 600dpi and for my certified files color scans are made.
Most every file I get from Attorneys, Title Companies and Realtors are the poorest quality the only works when viewed on a computer screen and when printed it is hardly dark enough to read.
I'm a self professed expert at scanning record survey documents, having personally done or controlled contracts for scanning over 700,000 documents.?ÿ I'll restrict my opinion to mylar survey maps/plats. *Assuming* they meet filing/recordation requirements, they should be "ink on mylar" pure black&white originals.?ÿ No grayscale, no color, no dithering.?ÿ If so, 200dpi use bitonal tiff with lossless CCITT T6 (Group 4) Fax compression for about 3-5Mb/scan and you'll have crisp scans as readable as the originals (update 2019, storage costs are down so 400dpi+ is now reasonable).
There's lots of other survey deliverables including deeds, colorful maps of some sort, ancient deteriorated plats, which may require special handling.?ÿ For example, can you read this fieldbook page??ÿ Would you trundle to the County Engineer's office to see the original??ÿ
OTOH, is this a useful scan?
