Help:Extension:Wikisource/Wikimedia OCR/es

The Wikimedia OCR feature of the Wikisource extension adds a toolbar interface to the main editing toolbar when editing in the Page namespace, to quickly extract text from the page image and add it to the page body text-box. OCR (siglas del inglés Optical Character Recognition) significa reconocimiento óptico de caracteres y es el proceso mediante el cual el texto de una imagen fotográfica se puede convertir en texto editable y, por lo tanto, agregarse a una wiki.

Para utilizar esta función, haga clic en el botón "Extraer texto" en el lado derecho de la barra de herramientas de edición principal. Esto ejecutará el proceso de OCR y agregará el texto resultante al campo del cuerpo de la página en el formulario de edición (reemplazando cualquier texto que ya esté allí). En la parte superior del campo del cuerpo se muestra un botón "deshacer", lo que le permite volver al estado anterior si lo desea.

Esta es la funcionalidad básica de Wikimedia OCR, pero hay algunas características avanzadas que pueden ser útiles en algunas circunstancias, disponibles a través del menú desplegable a la derecha del botón principal "Extraer texto". Estas funciones avanzadas le permiten elegir un motor de OCR diferente; establecer una lista de idiomas para ayudar al software a detectar palabras; o seleccionar un área más pequeña de la página desde la cual extraer texto. Todas estas funcionalidades avanzadas se explican a continuación. Tenga en cuenta que, además de la elección del motor, estas funcionalidades están disponibles a través del elemento del menú "Opciones avanzadas", que abre una nueva pestaña.



Motores OCR
There are currently three OCR engines available: Tesseract, Google and Transkribus. Tesseract is an open-source tool that runs in-house and supports a wide range of languages and other options. Google OCR is a proprietary service, also supporting lots of languages, but with fewer options. Transkribus is supported by an EU cooperative READ-COOP and has partnered with the Wikimedia Foundation to provide a limited number of free credits to support Wikisource Loves Manuscripts project.

The choice of which to use can vary depending on the nature of the image to be processed.

To switch engines, select the relevant radio button in the dropdown menu. Your choice will be remembered for your current device, and can be changed at any time.

Idiomas
Clicking the 'Advanced options' menu item opens a new tab with a transcription form containing a field for selecting the language or languages that are used in the page of text being extracted. This is useful because the OCR engines can be much more accurate when they know what languages to expect.

Note that not all languages are supported by all engines, and if you change the engine then the list of available languages will change too.

If your language is not in the list, you can leave the Languages field empty and the OCR engine will attempt to extract what text it can. This can have varying results, and is worth trying.



Area a seleccionar
To extract text from only a part of an image (for example, a single column of a page from a newspaper), it is possible to select a crop area. Do this by first clicking the crop button (, see screenshot at right), and then clicking and dragging over the page image to draw a rectangle. The image can be zoomed and panned, and the crop rectangle moved and resized as required. There are buttons above the image with which to switch between moving and cropping. Once you've selected the desired area, click 'Extract area' and the text for only that area will be shown in the right-side text box.

Returning from Advanced options
After using the advanced options form to extract text, it's necessary to copy and paste the resulting text back into the body field of the page editing form. To make this a bit quicker, a 'Copy to clipboard' button is provided.

First-time use
The first time you open a page for editing, a pulsating blue dot is shown on the 'Extract text' button. Clicking this dot or either of the buttons will open a popup explaining what this feature is. After this popup is dismissed, it will not be shown again (on the same device).

Issues
If you encounter any issues with using Wikimedia OCR, please report them on Phabricator, under the Wikisource OCR tag.