### Public Domain
Sources that have entered the public domain can often be found online on digital libraries like the [Internet Archive](https://archive.org/) or [Google Books](https://books.google.fr/). These sources consist of a collection of scans with an added layer of optical character recognition (OCR) which is, in most cases, not of any usable quality. Both types of data are combined into a PDF that can be downloaded.

### Archives
Archives and other memory institutions offer a wealth of material that has not yet been digitised. If you are struggling to obtain digital copies of the documents you are interested in, visiting the institution and requesting the digitisation of specific items may be necessary.  

As most memory institutions – slowly but surely – move into the digital age, your digitisation journey will usually begin in the comfort of your own home, searching through digital finding aids and preparing lists of the relevant institutions and archival materials to request for digital copies.  

Once the archival staff has prepared the required files for you, your work of selecting relevant archival materials begins. It is rare that an entire archival folder will be relevant to you. Here, a careful selection might save not only the time of the archivists doing the digitisation, but also your wallet.  

Most archives and other memory institutions have clearly defined conditions under which digital copies of archival material can be provided and how they can be used. These rules may be part of a general contract between the user and the particular archive, but in the case of a larger digitisation project it might be necessary to create a separate contract with project-specific rules.

Questions to ask yourself:
* What type of data do you need from the PDF? (text, paratext, digital object)
* Are you planning to research the sources or are you planning to republish the sources? (e.g. as part of training data for other ATR projects)

Depending on your objectives, you may be satisfied with:
* Using the Google Books PDF directly
* Obtaining a permissive license from the partner cultural heritage institution
* Creating an envelope dataset that does not contain the actual copyrighted object but enriches it with quality annotation such as transcriptions and only references the copyrighted digital object.

Digitisation of archival materials may be done directly by the user, but often the digitisation is carried out by a specialized department within the archive or an external provider. In this case, the user should specify the preferred quality of the digitised material so that it can fit the criteria for the subsequent ATR process. This service is usually chargeable and the final price is based on the number of items digitized.

### Specifications to take into account when digitising:
    * **Resolution**: 300 to 400 dpi (dots per inch).
    * **Colour space**: If you are scanning images yourself, make sure you are scanning in colour. It is the most effective way of recognising things in pictures, such as stamps or strange bleed-through effects, but also the script itself is much more cleaner in colour than bitonal. Colour can also help to make things clearer – boosting contrasts or even flipping colours around can make details stand out.
    * **File format**: For long-term archiving, formats such as ```TIFF``` of ```JPEG2000``` are often recommended or even required by research funders. They are very rich and large file formats. However, for processing image files with ATR, formats such as ```JPG```, ```PNG```, or ```PDF``` work just fine. If you need to change an image format into another, you can use converters. We recommend [ImageMagick](https://imagemagick.org/index.php), which is open source and free of charge.

When you are planning to publish your research outcomes, it might be helpful to consult the [Heritage Data Reuse Charter](https://www.dariah.eu/activities/open-science/data-re-use/), a DARIAH initiative. It contains 6 points on which cultural heritage institutions and researchers should agree upon when working together:
* **Reciprocity**: Do both cultural heritage institutions and researchers agree to share content and knowledge equally with each other, making use of data centres and research infrastructures?
* **Interoperability**: Cultural heritage data will be made accessible in a form that facilitates reuse of the data for research Formats should work and be interoperable for both scholars and cultural heritage institutions.
* **Citability**: Cultural heritage data and any resulting research need to be fully citable to increase their visibility and impact. Relevant data citation standards should be applied.
* **Openness**: Cultural heritage data should be shared under an open license whenever possible, taking into account existing copyright and any restrictions due to national legislation and privacy issues.
* **Stewardship**: Long-term preservation, persistence, accessibility, and legibility of cultural heritage data should be a priority.
* **Trustworthiness**: The provenance of cultural heritage data and any consequent research should be clear, up to date, openly available and therefore trustworthy.

Anna Busch

David Lassner

Aneta Plzáková

Anne Baillot

Mareike König

Whether photographed in an archive or discovered in the digital collections of memory institutions like libraries or museums, for many humanities scholars, images of text sources form the basis of their academic work. Finding, creating and collecting images of textual material is often the first step in the research process.

Edit actor

Other URLs relevant to the resource, e.g. ORCID, etc.

URL, ideally landing page, of the resource.

Person/group/body who helped create the resource.

Should be concise and raise interest in the entry. Allows <Link>Markdown</Link> content.

Other URLs relevant to the resource, e.g. code, DOI, etc.

Upload media

URL pointing to info about the access policy.

The activities you can do with the resource. See <Link></Link>.

Name of the conference where paper was given.

Describes the discipline covered by resource. See <Link></Link>.

Locations where the Resource is offered. See <Link></Link>.

URL to helpdesk for incidents & user requests.

Audience targeted by the resource. See <Link></Link>.

A particular published issue of a journal.

Concept or term related to MP entry. See <Link></Link>.

Language(s) in which a resource is available. See <Link></Link>.

Select license pertaining to resource. See <Link></Link>. If license is unknown, use the "Terms of use" property field to describe the usage terms.

Status of the Resource life-cycle. See <Link></Link>.

Mode of use for the resource. See <Link></Link>.

File format of the linked resource. See <Link></Link>.

Page #s of a resource, separate by commas.

Refine the resource's nature and function. See <Link></Link>.

Links to non-MP materials that are relevant.

Info about performance levels provider expected to deliver.

Standard used by the resource. See <Link></Link>.

Technology Readiness Level of the Resource. See <Link></Link>.

Resource user manual and documentation URL.

Version of the tool or service that is linked.

The volume of a journal or multivolume book.

Edit source

Name

If you are having trouble with the sign in process, please <ContactLink>contact the SSH Open Marketplace team</ContactLink>.

If you are having trouble with the sign up process, please <ContactLink>contact the SSH Open Marketplace team</ContactLink>.

Acquiring Images for Automatic Text Recognition

Media

Related items(1)

Automatic Text Recognition Roadmap

Workflow steps(4)

1 Find Images in Repositories

2 Define your Goals

3 Digitise Texts

4 Pay Attention to Copyright and Reuse Conditions: the Heritage Data Reuse Charter