wia_scan

wia_scan

Installation • Usage • License

Introduction

A simple utility for using document scanners that support Windows Image Acquisition (WIA) and is easy to install. If your scanner works using Windows Fax and Scan, there is a good chance it will work with this python script. This package allows you to create your own efficient scanning loop or use the one the one already provided.

Use cases:

• You have a flatbed scanner, and you need to scan a lot of documents, thus you don't want to use Windows Fax and Scan tool as it can introduce quite some overhead. This utility allows you to only press a few keystrokes in between scans, while you may need to turn the page or change the paper since you don't have an automatic feeding scanner like I don't.
• Support scanners in your own application on Windows using a simple Python dependency

The utility supports a simple calibration process which is fully visual. The reason for this process is that my scanner's default brightness (corresponding to brightness=0) is too bright.

Alternatives: Existing WIA libraries, but to my surprise the ones I found required quite old versions of Python, which I didn't want since I wanted to combine the scanning process with some modern Python packages.

Installation

Requirements:

• Windows
• Python ≥ 3.7

wia_scan can be installed from the package repository by running

pip install wia_scan

Alternative: From Source

Download the source code in this repository and install flit using pip install flit and run the following command from the source folder

flit install

Usage

Scan Many Documents

The main use case of this utility is to scan many documents using a few key presses, this can be achieved by running

wia_scan many

During the process, the utility will ask you beforehand which quality profile should be used for the next scan, and multiple sides can be combined into a single picture.

Command Line Interface

  wia_scan list_devices [-v]
  wia_scan single [--file=<output_file>] [--dpi=<dpi>] [--brightness=<brightness>]
                  [--contrast=<contrast>] [--mode=<mode>] [-v] [--uid=<uid>] [-q]
  wia_scan many [--out=<output_folder>] [--brightness=<brightness>] [--contrast=<contrast>] [-v]
  wia_scan calibrate brightness [--start=<start_range>] [--end=<end_range>]
                [--num_runs=<num_runs>] [--out=<output_folder>] [--uid=<uid>] [-q]
  wia_scan --help
  wia_scan --version

Options:
  -h --help                    Show this screen.
  --version                    Show version.
  -v --verbose                 Verbose output
  -q --quiet                   Quiet=no output
  --dpi=<dpi>                  Dots per inch; the higher this setting the higher the
                               output resolution [default: 200]
  --brightness=<brightness>    Brightness setting for the scanner, goes from -1000 to
                               1000 [default: 0]
  --contrast=<contrast>        Contrast setting for the scanner, goes from -1000
                               to 1000 [default: 0]
  --mode=<mode>                RGB for colored, L for grayscale [default: RGB]
  --file=<output_file>         Image output file
  --out=<output_folder>        Scanned images output folder [default: .]
  --start=<start_range>        Lowest value of brightness scanned [default: -200]
  --end=<end_range>            Highest value of brightness scanned [default: 200]
  --num_runs=<num_runs>        Number of scans for the "calibration" process [default: 9]

Library Usage - Custom Loop

Example: Create your own python file custom_loop.py and scan many single sided documents from the same scanner while waiting for a single key press between scans:

from wia_scan import *

device = prompt_choose_device_and_connect()
for i in range(1000000):
    press_any_key_to_continue()
    pillow_image = scan_side(device=device)
    filename = f'{i}.jpeg'
    pillow_image.save(filename, subsampling=0, optimize=True,
             progressive=True, quality=80)

License

wia_scan is distributed under the terms of the MIT license.