OCR Text Scanning
You can convert scanned text to digital documents and edit it!
With Optical Character Recognition (OCR) software, you can scan the printed word and put it in a format you can edit. Some documents scan better than others. If your document contains formatting, such as, indents, double spacing or tables, it may cause some of the text to adjust in the document when it has been scanned. However, this software is great if you have articles, book pages, or typewritten pages that do not contain additional formatting. It will even recognize pictures that are in the document. But it is supersensitive, so if you have pencil marks on the documents it will scan those too. However, this is a great option if you need to edit a document and do not want to re-type it.
Stop by Rm 19 in CMET at the Knight Library. Using our OCR software, you can also convert PDF files into Microsoft Office documents you can edit. It also lets you output a well formatted, searchable PDF file.
To scan graphics or text documents you do not need to edit, we can help you scan them on our flatbed scanners, and save them as a graphic filetype (ex. jpg, gif). We also have a slide/negative scanner.
A few basic tips to improve the quality of your scans.
- Scan at the right resolution
Most new users scan at too high a resolution. Too high a resolution will create huge files and increase processing time on your rip or your digital printer. Use the correct resolution for the intended output of digital files.
- Plan before you scan
Know the size you want the halftone to be in the finished piece. If you plan to reduce the image 50 percent, it will double the resolution. Reducing it 33 percent triples it.
- Use a retouching program
Clean up your scan in a retouching program such as Photoshop before using it in a layout program. The size and resolution should be set before placing them in a layout program. Crop the image while you are in the retouching program. White space creates data in the file and will make the file larger and take longer to rip or print. You will want to avoid using Quark or PageMaker to crop or rotate a scanned image.
- Scan the photo at the right Gamma
Gamma is a way of expressing changing a photo's overall brightness and contrast. It's a curve on a graph that changes a photo according to a number, such as 1.4, 2.2, or 0.8. The number is shorthand for the curve. It mostly changes the mid tones of a scan. In most photographs, the mid tones (the skin, for example) have most to the important detail. By either lightening or darkening these areas, you can bring out this detail.
If you make the change as the photo is scanned in, you will not degrade the quality of the image by adjusting it. If you scan a photo in and change the gamma afterwards, you will lose detail and tonality in one way or another.
The operator should increase brightness and contrast for most photos. The most common problem with desktop scanners is creating scans that are too dark. Most scanning software allows you to set gamma, and you can usually start with a 1.4 gamma and go higher if need be.
If your scanning software doesn't have a gamma adjustment, you can use brightness and contrast controls; increase both for more gamma, decrease both for less. This technique will not work quite as well.
- Adjust the photo to boost its tonal range
Make the darkest part of the photo as black as it can be and the lightest part as white as it can be, while making a smooth transition from black to white. Set the tonal range by using the Levels dialog. Set the black point slider just to the left of the end of the graph of the image, and the white point slider just to the right of the start of the graph.
Experiment with moving the mid tone point slider (gray) to improve the image further.
- Be sharp on screen
Make the on-screen image just a little sharper than you think is needed. It will soften in production. Use the Sharpening routine in the retouching program.
For more information, see Graphics and Digital Images.
Here are some other useful links.