Sometimes scanners don't return quite what you want them to. Likewise, perhaps scanservjs doesn't provide the defaults you want. Furtunately it's possible to override most things you might want to.
The two things you can modify are:
config: These are the global settings which include things like:- Server port
- Log level
- Preview resolution
- Output filename
- Pipelines (output format)
devices: The device definitions which are reported by SANE which include scanner dimensions and geometry, modes, resolutions and sources.
TL;DR; copy ./config/config.default.js to config/config.local.js, override
the sections you want and then restart the app
sudo systemctl restart scanservjs.service
If you are using docker, then you will want to map the configuration directory
e.g. -v /my/local/path:/app/config.
scanservjs looks for a file called config/config.local.js and attempts to call
two functions at different stages in the processing:
afterConfig(config): whenever a config is read, the result is passed to this function before being either used or sent down to the browser.afterDevices(devices): whenever the devices are read, the result is passed to this function before being used.- See example source for more options.
- Please note that the config file only gets read at start-up - so if you make changes, you will need to restart.
module.exports = {
/**
* @param {Configuration} config
*/
afterConfig(config) {
// Set default preview resolution
config.previewResolution = 150;
// Add a custom print pipeline
config.pipelines.push({
extension: 'pdf',
description: 'Print PDF',
commands: [
'convert @- -quality 92 tmp-%04d.jpg && ls tmp-*.jpg',
'convert @- scan-0000.pdf',
'lp -d MY_PRINTER scan-0000.pdf',
'ls scan-*.*'
]
});
},
/**
* @param {ScanDevice[]} devices
*/
afterDevices(devices) {
// Override the defaults for plustek scanners
devices
.filter(d => d.id.includes('plustek'))
.forEach(device => {
device.features['--mode'].default = 'Color';
device.features['--resolution'].default = 150;
device.features['--resolution'].options = [75, 150, 300, 600];
device.features['--brightness'].default = 0;
device.features['--contrast'].default = 5;
device.features['-x'].default = 215;
device.features['-y'].default = 297;
});
}
};You have an old Canon flatbed but it returns daft default values for width and height. You also want to change the default resolution and limit the resolution options.
/**
* @param {ScanDevice[]} devices
*/
afterDevices(devices) {
// Override the defaults for plustek scanners
devices
.filter(d => d.id.includes('plustek'))
.forEach(device => {
device.features['--resolution'].default = 150;
device.features['--resolution'].options = [75, 150, 300, 600];
device.features['-x'].default = 215;
device.features['-y'].default = 297;
});
}Some scanners (I'm looking at you, Brother) report their dimensions incorrectly. This throws off the cropping logic because scanservjs incorrectly trusts the SANE output.
afterDevices(devices) {
devices
.filter(d => d.id.includes('brother'))
.forEach(device => {
device.features['-l'].limits = [0, 215];
device.features['-t'].limits = [0, 297];
device.features['-x'].default = 215;
device.features['-x'].limits = [0, 215];
device.features['-y'].default = 297;
device.features['-y'].limits = [0, 297];
});
}If you have many scanners available then you may wish to give devices friendly
names as per #212.
{ScanDevice} objects have a name attribute which defaults to the id but
can be anything you want it to be. You just need to override it.
afterDevices(devices) {
const deviceNames = {
'plustek:libusb:001:003': 'Downstairs Canon Flatbed',
'test:device:unreal': 'Upstairs Canon MFD'
};
devices
.filter(d => d.id in deviceNames)
.forEach(d => d.name = deviceNames[d.id]);
}You may wish to add your own custom pipelines. Pipelines are arrays of shell commands which run after scans. To learn more read the example source. This will insert your own pipelines at the top of the list.
afterConfig(config) {
const pipelines = [
{
extension: 'jpg',
description: 'TEST PIPELINE | Terrible quality',
commands: [
'convert @- -quality 20 scan-%04d.jpg',
'ls scan-*.*'
]
},
{
extension: 'jpg',
description: 'TEST PIPELINE 2 | Silly quality',
commands: [
'convert @- -quality 99 scan-%04d.jpg',
'ls scan-*.*'
]
}
];
config.pipelines.splice(0, 0, ...pipelines);
},ocrmypdf is a tool which deskews crooked scans, automatically fixes incorrectly rotated pages and performs OCR with tesseract. It needs to be installed separately, see the official instructions.
Then, add the following pipeline:
config.pipelines.push({
extension: 'pdf',
description: 'ocrmypdf (JPG | @:pipeline.high-quality)',
get commands() {
return [
'convert @- -quality 92 tmp-%04d.jpg && ls tmp-*.jpg',
'convert @- pdf:-',
`ocrmypdf -l ${config.ocrLanguage} --deskew --rotate-pages - scan_0000.pdf`,
'ls scan_*.*'
];
}
});const dayjs = require('dayjs');
module.exports = {
afterConfig(config) {
config.filename = () => {
return `my_filestem_${dayjs().format('DD-MM-YYYY HH-mm-ss')}`;
};
config.log.level = 'DEBUG';
}
}Exercise caution with this recipe - the app is designed not to allow unsafe paths by default. If you are happy to disable this check, then go ahead.
module.exports = {
afterConfig(config) {
// Set your path here
config.outputDirectory = '/home/me/scanned';
// By default paths with `..` or `/` are not allowed
config.allowUnsafePaths = true;
}
}You can use a filter to include only the paper sizes you want. To only show ISO sizes do something like the following. You can obviously extend or reverse the filter as required.
module.exports = {
afterConfig(config) {
config.paperSizes = config.paperSizes.filter(p => /[AB]\d/.test(p.name));
}
}