Scanning with SANE and Other Tools

The only scanner maker to support the SANE Project actively is Epson. The Epson KOWA Corporation has released their own front end, known as Image Scan!, along with an updated back end that unifies support for all current Epson scanners. This product has the advantage of providing updated drivers for off-the-shelf scanners directly from the manufacturer.

Figure 3. The Image Scan! Front End Managing the Epson Perfection 1260

This front end is less sophisticated than XSane or QuiteInsane, providing fewer features, yet it has a cleaner, less cluttered interface. It also lacks a built-in image viewer, opting to use either The GIMP specifically for image editing or saving scans directly to a file or a printer. There is no built-in help and little on-line documentation.

XSane, QuiteInsane and Image Scan! all function as front-end user interfaces to the SANE back-end scanner drivers. However, one other scanner product does not use the SANE back ends at all: VueScan from Hamrick Software. This product is shareware and provides its own set of scanner drivers for a wide variety of scanners.

Figure 4. The VueScan Front End Managing the Epson Perfection 1260

VueScan offers many features not provided by the front ends to SANE, such as device calibration, focus and exposure. It does not provide image editing or a GIMP plugin. Scans need to be saved to file first, then opened in an image editor.

Of the four front ends, only one is limited to one vendor—Image Scan!, which supports only Epson scanners. The other three support various vendors. All front ends provide variations on gamma and color channel correction either before or after a scan, or both in some cases. XSane, QuiteInsane and VueScan all provide a built-in image viewer with limited image editing capabilities. Image Scan! scans only to a file or directly into The GIMP.

The areas of largest differentiation in all four front ends are where scans can be sent and how they can be printed. XSane offered the most destinations for scans, including e-mail and FAX. Optical character recognition (OCR) is supported by both XSane and QuiteInsane through the external gocr program.

XSane, QuiteInsane and Image Scan! provide a continuous update to the preview display when a preview scan is in progress. This means you can watch the scan as it happens. The same is true for full scans. VueScan does not provide continuous updates.

Printing is by far the biggest difference in all four. QuiteInsane is the only front end that offers printing from the application, with various print options. XSane can scan directly to the printer, but you can't print a scan from the built-in image viewer. VueScan offers printing from the image viewer, but the interface is clunky and lacks features.

Documentation for both XSane and QuiteInsane is extensive and fairly well written. HTML documentation is also provided for VueScan but is far less complete. Image Scan! has a minimalist man page.

All of the open-source tools provide GIMP plugins, though VueScan does not. XSane's plugin is the most advanced in stability. QuiteInsane's plugin is feature-rich but is under early development and may not be as stable as users might prefer. Image Scan!'s plugin is functionally equivalent to its standalone version, while XSane and QuiteInsane offer slightly modified versions for their GIMP plugins.

Table 1 is a comparison of the four scanner front ends. Although this table is a good tool for choosing which front end to start with, you would be missing out if you didn't at least try each of them.

Table 1. Scanner Front-End Comparisons

All scans for XSane and QuiteInsane will be essentially the same because of the use of the common SANE back ends. Image Scan! includes a driver that provides the same level of quality as the Epson Windows driver. VueScan's driver is its own. In Figure 5, the two scans compare the Epson and the VueScan driver. Figure 6 shows a close-up of these scans around the eyes. The SANE version has a smoother transition between pixels, and the VueScan provides more detail in the reflection in the left eye.

Figure 5. Comparison: Left—SANE; Right—VueScan. JPEG quality was set to 100 for the SANE version.

Figure 6. Close-up of the SANE (Epson) and VueScan scans showing variations in quality.