How to use the command 'scanimage' (with examples)

The scanimage command is a versatile tool used for scanning images using the Scanner Access Now Easy (SANE) API. SANE provides a standardized interface to access scanners, making it possible to initiate scans and manage scanned images through command-line interfaces. scanimage is particularly useful for automated workflows and scripts in environments where GUI applications are not ideal.

Use case 1: List available scanners to ensure the target device is connected and recognized

Code:

scanimage -L

Motivation:

Ensuring that the scanner is correctly connected and recognized by your system is a crucial first step before proceeding with any scanning job. This use case allows you to verify whether your scanning device is available, avoiding wasted time and effort in debugging connectivity issues during the scanning process. It’s particularly useful in environments with multiple devices to help you identify and select the right scanner.

Explanation:

• scanimage: This is the command that utilizes the SANE API for scanner operations.
• -L: This option lists all the scanners that are currently available and recognized by SANE. It does not initiate any scanning but rather queries the status of the system’s available scanning devices.

Example Output:

device `epson2:libusb:001:004' is a Epson perfection V370 flatbed scanner

This output indicates that the system has successfully recognized an Epson Perfection V370 scanner, identified by its unique ID. If multiple scanners are present, each will be listed with its respective details.

Use case 2: Scan an image and save it to a file

Code:

scanimage --format=pnm > path/to/new_image.pnm

Motivation:

Once your scanner is confirmed to be available and properly connected, the next logical step is to perform the scanning operation. This use case demonstrates how to execute a scan from the command line and save the resulting image to a specified file. By doing this via command line, users can easily automate and script the scanning process, integrate it into larger workflows, or even control the scanner remotely. This specific command provides flexibility in choosing the desired image format, ensuring compatibility with various image processing tools.

Explanation:

• scanimage: Calls the SANE API to perform a scanning operation.
• --format=pnm: Specifies the format of the output image. In this instance, it instructs scanimage to save the scanned image in PNM (Portable Anymap) format, which is a versatile image format supported by many software tools. Other supported formats include tiff, png, and jpeg, which can be chosen based on user needs and compatibility with other applications.
• >: The shell redirection operator, which directs the output from the scanimage command (the scanned image) into a file.
• path/to/new_image.pnm: The filesystem path where the scanned image will be saved. The filename extension should match the format specified to ensure compatibility where other applications are concerned.

Example Output:

Scanned page 1. (scanner status = 5)

This message indicates that scanimage has successfully scanned page 1 of your document, with the scanned data saved in the specified output file. Any subsequent scans or pages will be processed similarly, providing feedback on the operation’s success or any potential issues.

Conclusion:

The scanimage tool offers a robust command-line method for interacting with scanners supported by the SANE API. By using the examples outlined above, users can effectively list available scanners to ensure everything is connected properly and perform a scan while saving the results to an accessible file format. Its flexibility and ease of use make it a valuable tool for both casual users and system administrators who require batch processing capabilities or remote scanner management.