Another Format Question

[Frank Zwolinski]

Hello, again I am curious as to what others do with scanning.

I now scan all photos at 600dpi unless they need to be greatly enlarged then I go higher. However my question today is other documents, abstracts, typed and handwritten documents, line drawings, etc. I have been using 300dpi and saving as a PDF with my scanners Text setting and the files are small under 100 KB, if I use the B/W setting they are over a MB. And this scanner will not scan as a jpg in the Text mode, but it will in the B/W mode. Are the smaller files, above sufficient?

Your suggestions are appreciated.

Frank

[Bob White]

Re: Another Format Question

Apples and oranges, Frank. What you are calling Text mode is OCR which stands for Optical Character Recognition. In that mode, the scanner is sending the shapes it "sees" to an OCR program for processing to create a text document. All those other modes are like a camera; they are just taking a picture.

By the way, there is not really a need to scan at 600 dpi unless you plan to publish the scanned item at larger physical sizes. (Yes, there will be other opinions.)

[theKiwi]

Re: Another Format Question

There is no reason to not scan at at least 600dpi.

Roger

[Frank Zwolinski]

Re: Another Format Question

Ah! That's what I like about this list, so many opinions, so many choices. My question still remains, which format and what dpi is best for these printed and handwritten documents.

Thank you gentlemen.

Frank

[donworth]

Re: Another Format Question

I scan printed stuff in color, JPG, medium compression at 300 dpi. Although anything over about 150 dpi is usually pretty legible.

Usually B&W scans are smaller than color, unless the B&W's are being stored in non-compressed formats (like GIFs or BMP). So that part of your question doesn't make sense to me. I have also found that PDFs tend to "bloat" - they can be larger than the equivalent JPG file.

W/re to scanning photos. I scanned all my old photos at 200 dpi back in the 90s and ended up having to rescan them all recently at 600 dpi. The problem with scanning at low resolutions is that you aren't really preserving the whole photo for posterity and you never know, down the line, what use you are likely to put it to. What if you wanted to make a 5x7 print from it someday? or you wanted to enlarge a section to try to read a sign in the background? It's not just if you want to publish it. Also, as you mentioned, some of these tiny photos (carte de visites and such) might need enlargement, so more pixels is nice to have. These days scanners are very fast at 600 dpi, and the files are still less than a megabyte (if in compressed JPG) and storage is dirt cheap. I am not, however, a TIF nazi - a 600 dpi JPG in medium compression is just fine if you ask me.

Sorry, Bob set me off! ha ha...

Don

[Bob White]

Re: Another Format Question

I love it.... everyone has an opinion and doesn't mind sharing it.

[Frank Zwolinski]

Re: Another Format Question

To clarify Don's confusion with this statement of mine:
"I have been using 300dpi and saving as a PDF with my scanners Text setting and the files are small under 100 KB, if I use the B/W setting they are over a MB. And this scanner will not scan as a jpg in the Text mode, but it will in the B/W mode. Are the smaller files, above sufficient?

I have two scanners, a flatbed and one with a sheet feeder but the software with each is different. On the flatbed I have three "kinds" to choose from, "Text," "Black & White," and "Color." If I use the "Text kind" I have format options of, TIF, PNG, and PDF. If I use the "B&W kind," I have format options of, JPEG, TIFF, PNG, JPEG 2000, and PDF. If I use the "Color kind" I have these options, JPEG, TIFF, PNG, JPEG 2000, GIF, BMP and PDF. So I have tried several options (at 300 dpi) to see what the file size would be. Since I cannot do a JPG with the "Text kind," and I am scanning handwritten or typed documents, I do a PDF and get a 78KB file, If I do the same document with the "B&W kind," I get a 5.7MB document, "Color kind" gives me a 17.8MB file. So you see that the Text PDF at 300 gives me a small file and while I have looked at it on the screen and even when enlarged, I just wondered if the small file size is a safe bet to use for the future or do I need to go larger. I like you would like NOT to have to rescan in the future.

The current documents I am scanning are printed abstract forms (8.5X11) with the information handwritten in the blanks. It is unlikely that I will need to enlarge these documents in the future and a printed version of the smaller file size turns out looking just fine.

So I hope this clears up your confusion. If not, we could talk off line if you like. It just seems a bit silly/wasteful to have a multi-megabite file for these specific documents.

Gentlemen, please continue to add to the discussion as it only adds to my knowledge base.

Thank you both!!

Frank

[donworth]

Re: Another Format Question

Frank,

It kind of sounds like the "text" mode scans without grayscale (just black and while, no shades of gray) and then maybe compresses it in the PDF file. B&W obviously has grayscale (which increases the file size) as does color. It also sounds like they are storing the JPGs without any compression or you wouldn't be getting multi-megabyte files off an 8.5x11 image. As a point of comparison, an 8.5x11 handwritten page of interview notes I scanned at 200dpi, color, JPG, medium compression is a 300Kb file.

If what you get that is under 100Kb satisfies you and is legible when you print it, then I would think that would be fine. The only reason I scan at a higher resolution in color (or, at least grayscale) for handwritten stuff is that sometimes there are areas that are illegible (someone crossed something out and tried to correct it and I can't read any of it.) In those cases, I blow it up in Photoshop to see which strokes of the pen seem to connect to which, etc. Or sometimes they use a very faint pencil so I have to enhance the levels on the image to read it properly. This has been particularly important when scanning old (1860s) letters written in fountain pen or pencil where there is a lot of dirt on the page along with the handwriting.

I'm surprised your software doesn't have an "expert" mode or "professional" mode or some such. Usually there is a way to get more explicit about how you want things handled in the scanner. Sounds like worst case you can output in color to TIF, then load the resulting gigantic file into a photo editing application (like the one Bob recommended or Photoshop or ???) and make it B&W grayscale and compressed JPG output. Then delete the huge file. But that's an extra step admittedly.

You can, also, get 3rd party software to drive your scanner. There are stand-alone applications like Silverfast or VueScan that replace the software that came with your scanner and are much more fully functional. Or you often get a TWAIN plug-in with your scanner which you can use with Photoshop or other image editing applications that allow you to scan directly into them without going into a file first. Then you have complete control over how the file gets stored.

[Robert Godfrey]

Re: Another Format Question

Photoshop offers the ability to batch process a folder of images into PDF files.

Preview will also print a batch of images as PDF; however, it will save the batch as separate pages within one PDF file, so you'd need to separate the pages into individual files.