Document Number 2203 Recognition Hints and Tips for CatchWord Pro for Windows 10/26/92 1. Always scan in line-art or black and white mode. There is a feature in CatchWord Pro for Windows which allows you to scan in 256 grayscale with the ScanMan 256 if your original has a colored background. After the scanning process the program converts the image back to line-art to give the best contrast possible. This feature should only be used for originals which do not have white backgrounds. Otherwise, scan in line-art mode. 2. Selecting The Right Resolution Most magazines and text books should be scanned at 300 dpi. Use 400 dpi if the text you are scanning is smaller than standard magazine size. For normal sized text (8 to 15 points), 300 dpi is the best resolution. Use 200 dpi if you are scanning large blocks of headline-style type. Text Size Scanner Resolution (DPI) ---------------------------------------------- 6 to 8 Points 400 DPI gives best results 9 to 15 Points 300 DPI gives best results 16 to 20 Points 200 DPI gives best results 3. Adjusting Contrast Contrast control (the relative amounts of black and white) is critical in obtaining a good scan. If the text to be scanned is too faint and the scanned image shows excessive broken characters, then the recognition will be poor due to the unrecognized characters. If the scan is too dark, the letters will run together and cause poor recognition. In any initial scanning of a new image, you will need to adjust the contrast. CatchWord Pro for Windows tends to prefer a darker contrast, so start with the contrast setting slightly darker than the middle notch on the scanner. 4. Scanning Speed For the best image quality, experiment with the scanning speed to determine the best rate for your computer. You should be scanning at an acceptable rate so the speed indicator light on the scanner head does not flash. When you scan too fast the characters may look compressed, which causes character size inconsistencies. Try to scan a bit slower than the normal rate recommended by the scanner software, perhaps at about 1/2 to 1 inch per second. This way the system can receive and process all of the incoming scanned data in time. Make sure your scanning does not get too far ahead of the real-time display. On slower machines the disk access speed cannot keep up the with the rate of incoming data passed from the scanner to the machine channel. Before you hit RETURN to activate Recognition, view the entire image to check whether all the data is captured to screen. When you have scanned too fast for the system, you may notice the final image displayed will have loss of data, i.e., certain chunks of paragraphs are missing. In this case, you will have to rescan slower. Scanning too slowly will not affect the quality of the scanned image. 5. Scanning Straight When the actual scan is slanted, skewed, or jagged, the text will not be recognized fully. Use a hard edge ruler or the edge of a book to help scan straight. 6. Practice! As you become more and more familiar with the way CatchWord Pro works - what it recognizes and what it doesn't - you will find your results increase dramatically. 7. Full Page Scanning You get best results scanning horizontally when attempting to scan a full page. Be sure to select the landscape multiple strip scan mode icon. Begin and end each strip at the same place on the page, and overlap four lines of text. You may need to scan in three strips instead of two to get the full page scanned. TROUBLESHOOTING Following are the most common reasons why an OCR program may misread text: Unrecognizable fonts or characters. Omnifont technology recognizes standard fonts by comparing text characters to features programmed into the software. The software will not read characters which don't match programmed features. It may also misread similar characters, for example 1 and l. Original document quality directly affects accuracy. Letters which are faint, touching or otherwise illegible may be read inaccurately. Newspapers, copies and faxes are often poor originals. Uneven or fast scanning, or pausing in mid-scan may result in skewed, stretched or compressed text. Follow the tips above to avoid these causes for misrecognition.