#3462- CorelSCAN™ 8 and Scanning Issues Scanning is the process of converting an image that is on paper, film, or slide to a digital format that computers can understand. A scanning device, such as a hand-held scanner, flatbed, or drum, converts light reflected from the surface of an image, into digital information which can be read by a computer. The scanning device's sensors collects the red, green, and blue light information from the light reflected and sends it to the computer. Some scanners are connected via the parallel printer port or a proprietary scanner card. Use the scanner's own TWAIN drivers and/or software if there are problems using CorelSCAN™ 8. This document contains the following sections: - CorelSCAN 8 - Troubleshooting Scanner Problems - Scanning Tips CorelSCAN 8 is a utility program that guides the user with a wizard interface through the scanning process. In a Typical installation of CorelDRAW™ 8, CorelSCAN will be installed. Run a custom setup of CorelDRAW 8 if CorelSCAN is currently not installed. Note: If the system is running Windows NT® 4.0, Service Pack 3 must be installed in order for scanning to work properly. To determine if the Service pack 3 installed, go to Start, Programs, Administrative Tools, Windows NT Diagnostics > Version= Build (1381: Service Pack 3). To obtain Service Pack 3, contact Microsoft at http://www.microsoft.com. For specific scanner compatibility issues with CorelSCAN, click on Start, Programs, CorelDRAW 8, Setup and Notes, Corel Readme. CorelSCAN will distribute if required, the following systems files in Windows® 95 and Windows NT 4.0: TWAIN.DLL Version 1,6,0,3 These files are located in the root folder of TWAIN_32.DLL Version 1,6,0,3 windows or win NT in both Windows 95 TWUNK_16.EXE Version 1,6,0,1 and Windows NT 4.0. TWUNK_32.EXE Version 1,6,0,1 To launch CorelSCAN: A. Start, Programs, CorelDRAW 8, Graphic Utilities, CorelSCAN 8, or B. Open CorelDRAW 8 or Corel PHOTO-PAINT™ 8 and select File, Acquire, Acquire from CorelSCAN. 1. In the Welcome to CorelSCAN screen, choose the scanner driver and click on Configure Scanner. Note: Use Advanced Interface to use the scanner's interface instead of CorelSCAN's. Enabling this allows scanning in a single step using the options saved in the settings you choose from the Preset list box. 2. Select a Device Color Profile for the scanner. If the scanner uses its own color correction scheme, select None for Profile. 3. If multiple twain sources are installed on the system, select the source to be configured from the Driver Name list box. 4. Ensure that the Scanner Type is correct in the Scanner Type list box. 5. Click on Test Scanner Driver. Wait until this process has completed. 6. Click Finish. To scan using CorelSCAN and the new configuration, choose the Scanner Driver "FlatBed" UI. Selecting the Scanner Driver "Driver UI" allows scanning using the driver's own interface. (Note: The new configuration may not be named "Flatbed" if the scanner happens to be a Handheld or other. The new configuration will have the Scanner Type in parentheses) 7. When using CorelSCAN, the wizard will display selections concerning the type of scan being performed. To obtain more information, select HELP, or click on the ? and click on the text/dialog, or select the item and look at the preview result in the window. If the compatibility test fails with the scanner's twain source, scanning can still be done using the driver's own UI. Troubleshooting Scanner Problems Installation for Non Twain-Compliant Scanners (16-bit or 32-bit) Scanners which are not Twain-compliant must be installed as stand-alone components. Use the software supplied with the scanner to install it on the computer. The scanned images may be saved to a file from the scanning application and then imported into Corel PHOTO-PAINT or Corel OCR-TRACE™, or CorelDRAW™. Error Messages 1. TWAIN ERROR - No Scanner Source Found The system is equipped with a 16-bit adapter, or the scanner is connected via a parallel port or a non-SCSI interface card. Verify this by clicking Start, Settings Control Panel. Double-click the System icon, and click Device Manager. If the [!] warning is displayed on the adapter or an adapter does not appear, the computer is equipped with a 16-bit adapter and software, or Windows 95 does not recognize the adapter. This may be resolved by obtaining a Windows 95 supported 32-bit driver. 2. TWAIN ERROR - Communications Errors Ensure the connection from r scanner and computer is secure. Try scanning from the scanner's own scanning program. Close down any open programs and ensure there is adequate free hard disk space. 3. TWAIN DRIVER ERROR - Sorry, could not find the Twain Source Manager (Twain_32.dll). Copy the Twain Source Manager TWAIN_32.DLL from the CD#1 located in the TWAIN folder to the Windows folder. 4. FATAL ERROR - Could not find C:\WINDOWS\TWAIN_32\XXX\XXX32.dll(ds) Reinstall the vendor supplied scanner software/drivers. 5. SCSI ERROR - No Scanner! Scanner is not installed, not connected, or was not turned on before booting the computer. 6. TWAIN DRIVER ERROR - Sorry, there is a TWAIN error The scanner is not connected, or was not turned on before booting the computer. Ensure the Scanner is turned on first, then restart the computer. 7. OUT OF MEMORY messages when scanning - ensure there is adequate free disk space - add more memory to the computer - scan at a lower resolution such as 100 or 200 dpi - under Windows NT 4.0, go to Start, Settings, System, Performance. Change Virtual Memory by increasing both the Initial and Maximum Size settings. - Under Windows 95, if the machine has 32 or 64 MBs of RAM, try adding the below two lines in the system.ini file in windows. 1. Start, Run, System.ini [vcache] MaxFileCache=6144 MinFileCache=1024 save the file and restart Windows 95 General Troubleshooting Steps 1. Ensure the latest Windows 95 or Win NT 4.0 compliant driver is installed for the SCSI adapter card. 2. Ensure the scanner is correctly installed and powered on first before turning the computer on. In Windows 95, determine if there are any device conflicts in Device Manager (Start, Settings, Control Panel, System, Device Manager). 3. Ensure the monitor is displaying 256 colors or more. To obtain better results, the monitor should be capable of displaying High Color 16 bit (65,536 colors) or higher. In Windows 95/Windows NT 4.0 go to Start, Settings, Control Panels, Display, settings to change the color palette level. 4. Close down any programs that may be opened. In Windows 95 press Ctrl + Alt + Del to determine what programs may be opened. Do not close Explorer in Windows 95. For Windows NT 4.0, press Ctrl + Alt + Del, select Task Manager, Applications to determine any programs running. 5. Determine if scanning works properly from the scanner's software or if the scanner can perform a self-test. 6. Rename the TWAIN and TWAIN_32 Folders in the Windows folder. Rename the TWAIN.DLL and TWAIN_32.DLL files in Windows. Then reinstall the drivers that came with the scanner. Restart the computer. Scanning Tips When scanning images, determine what the scanned image will be used for? If the images are to be viewed on the screen, scan at 100 dpi (dots per inch). For web graphic images, scan at 72 dpi. The question becomes more complicated when printing or outputting the scanned image. Since a scanner scans square pixels and a printer prints round dots, a scanned pixel is not equal to a printer dot. Each scanner pixel can come in 16.7 million colors and is measured in an inch square. A 600 dpi scan would be 1/600 of an inch square. Each printer dot can only have two values. The size of the printer dot is based on the dpi of the printer. The size of a dot on a 600 dpi printer is 1/600 of an inch. A combination of dots creates a halftone and is used to create the colors needed. A better way to measure printer output is lpi (lines per inch). The general rule of thumb is to scan at 1.5 times the line frequency of the final output device. An older practice was to scan at 2.0 times the line frequency. Most scans can be performed between 100 to 200 dpi as shown in the table below: dpi of printer default line screen scanning dpi (1.5 x default line screen) 300 60 90 600 80 120 1000 100 150 1200 133 200 * Recommended dpi will vary if the output image size will be larger or smaller than the original image size. Use this formula to determine the optimal scanning resolution: SCAN = (( LDO x LS) x 1.5) LDI SCAN = Optimal scanning resolution in dpi LDO = Longest dimension of the output image in inches LS = Line screen of output device LDI = Longest dimension of the input image in inches (physical size of document being scanned) * Black and White Images only may be scanned at the same dpi as the output device so for a 600 dpi printer, scan the image at 600 dpi at black and white. If the black and white image has a lot of detail try scanning as grayscale to improve image quality. For a scanned image that is crooked, use the deskew feature (Image > Deskew in the menu) of PHOTO-PAINT 8 to straighten out the image.