branch: externals/scanner
commit 3f83066fc6a471051c31a2d005530e146339383d
Author: Raffael Stocker <r.stoc...@mnet-mail.de>
Commit: Raffael Stocker <r.stoc...@mnet-mail.de>
add info manual stub
* fdl.texi: new file (GNU FDL)
* scanner.texi: new file (manual)
---
fdl.texi | 505 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
scanner.texi | 481 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 986 insertions(+)
diff --git a/fdl.texi b/fdl.texi
new file mode 100644
index 0000000000..eaf3da0e92
--- /dev/null
+++ b/fdl.texi
@@ -0,0 +1,505 @@
+@c The GNU Free Documentation License.
+@center Version 1.3, 3 November 2008
+
+@c This file is intended to be included within another document,
+@c hence no sectioning command or @node.
+
+@display
+Copyright @copyright{} 2000, 2001, 2002, 2007, 2008 Free Software Foundation,
Inc.
+@uref{https://fsf.org/}
+
+Everyone is permitted to copy and distribute verbatim copies
+of this license document, but changing it is not allowed.
+@end display
+
+@enumerate 0
+@item
+PREAMBLE
+
+The purpose of this License is to make a manual, textbook, or other
+functional and useful document @dfn{free} in the sense of freedom: to
+assure everyone the effective freedom to copy and redistribute it,
+with or without modifying it, either commercially or noncommercially.
+Secondarily, this License preserves for the author and publisher a way
+to get credit for their work, while not being considered responsible
+for modifications made by others.
+
+This License is a kind of ``copyleft'', which means that derivative
+works of the document must themselves be free in the same sense. It
+complements the GNU General Public License, which is a copyleft
+license designed for free software.
+
+We have designed this License in order to use it for manuals for free
+software, because free software needs free documentation: a free
+program should come with manuals providing the same freedoms that the
+software does. But this License is not limited to software manuals;
+it can be used for any textual work, regardless of subject matter or
+whether it is published as a printed book. We recommend this License
+principally for works whose purpose is instruction or reference.
+
+@item
+APPLICABILITY AND DEFINITIONS
+
+This License applies to any manual or other work, in any medium, that
+contains a notice placed by the copyright holder saying it can be
+distributed under the terms of this License. Such a notice grants a
+world-wide, royalty-free license, unlimited in duration, to use that
+work under the conditions stated herein. The ``Document'', below,
+refers to any such manual or work. Any member of the public is a
+licensee, and is addressed as ``you''. You accept the license if you
+copy, modify or distribute the work in a way requiring permission
+under copyright law.
+
+A ``Modified Version'' of the Document means any work containing the
+Document or a portion of it, either copied verbatim, or with
+modifications and/or translated into another language.
+
+A ``Secondary Section'' is a named appendix or a front-matter section
+of the Document that deals exclusively with the relationship of the
+publishers or authors of the Document to the Document's overall
+subject (or to related matters) and contains nothing that could fall
+directly within that overall subject. (Thus, if the Document is in
+part a textbook of mathematics, a Secondary Section may not explain
+any mathematics.) The relationship could be a matter of historical
+connection with the subject or with related matters, or of legal,
+commercial, philosophical, ethical or political position regarding
+them.
+
+The ``Invariant Sections'' are certain Secondary Sections whose titles
+are designated, as being those of Invariant Sections, in the notice
+that says that the Document is released under this License. If a
+section does not fit the above definition of Secondary then it is not
+allowed to be designated as Invariant. The Document may contain zero
+Invariant Sections. If the Document does not identify any Invariant
+Sections then there are none.
+
+The ``Cover Texts'' are certain short passages of text that are listed,
+as Front-Cover Texts or Back-Cover Texts, in the notice that says that
+the Document is released under this License. A Front-Cover Text may
+be at most 5 words, and a Back-Cover Text may be at most 25 words.
+
+A ``Transparent'' copy of the Document means a machine-readable copy,
+represented in a format whose specification is available to the
+general public, that is suitable for revising the document
+straightforwardly with generic text editors or (for images composed of
+pixels) generic paint programs or (for drawings) some widely available
+drawing editor, and that is suitable for input to text formatters or
+for automatic translation to a variety of formats suitable for input
+to text formatters. A copy made in an otherwise Transparent file
+format whose markup, or absence of markup, has been arranged to thwart
+or discourage subsequent modification by readers is not Transparent.
+An image format is not Transparent if used for any substantial amount
+of text. A copy that is not ``Transparent'' is called ``Opaque''.
+
+Examples of suitable formats for Transparent copies include plain
+ASCII without markup, Texinfo input format, La@TeX{} input
+format, SGML or XML using a publicly available
+DTD, and standard-conforming simple HTML,
+PostScript or PDF designed for human modification. Examples
+of transparent image formats include PNG, XCF and
+JPG@. Opaque formats include proprietary formats that can be
+read and edited only by proprietary word processors, SGML or
+XML for which the DTD and/or processing tools are
+not generally available, and the machine-generated HTML,
+PostScript or PDF produced by some word processors for
+output purposes only.
+
+The ``Title Page'' means, for a printed book, the title page itself,
+plus such following pages as are needed to hold, legibly, the material
+this License requires to appear in the title page. For works in
+formats which do not have any title page as such, ``Title Page'' means
+the text near the most prominent appearance of the work's title,
+preceding the beginning of the body of the text.
+
+The ``publisher'' means any person or entity that distributes copies
+of the Document to the public.
+
+A section ``Entitled XYZ'' means a named subunit of the Document whose
+title either is precisely XYZ or contains XYZ in parentheses following
+text that translates XYZ in another language. (Here XYZ stands for a
+specific section name mentioned below, such as ``Acknowledgements'',
+``Dedications'', ``Endorsements'', or ``History''.) To ``Preserve the Title''
+of such a section when you modify the Document means that it remains a
+section ``Entitled XYZ'' according to this definition.
+
+The Document may include Warranty Disclaimers next to the notice which
+states that this License applies to the Document. These Warranty
+Disclaimers are considered to be included by reference in this
+License, but only as regards disclaiming warranties: any other
+implication that these Warranty Disclaimers may have is void and has
+no effect on the meaning of this License.
+
+@item
+VERBATIM COPYING
+
+You may copy and distribute the Document in any medium, either
+commercially or noncommercially, provided that this License, the
+copyright notices, and the license notice saying this License applies
+to the Document are reproduced in all copies, and that you add no other
+conditions whatsoever to those of this License. You may not use
+technical measures to obstruct or control the reading or further
+copying of the copies you make or distribute. However, you may accept
+compensation in exchange for copies. If you distribute a large enough
+number of copies you must also follow the conditions in section 3.
+
+You may also lend copies, under the same conditions stated above, and
+you may publicly display copies.
+
+@item
+COPYING IN QUANTITY
+
+If you publish printed copies (or copies in media that commonly have
+printed covers) of the Document, numbering more than 100, and the
+Document's license notice requires Cover Texts, you must enclose the
+copies in covers that carry, clearly and legibly, all these Cover
+Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on
+the back cover. Both covers must also clearly and legibly identify
+you as the publisher of these copies. The front cover must present
+the full title with all words of the title equally prominent and
+visible. You may add other material on the covers in addition.
+Copying with changes limited to the covers, as long as they preserve
+the title of the Document and satisfy these conditions, can be treated
+as verbatim copying in other respects.
+
+If the required texts for either cover are too voluminous to fit
+legibly, you should put the first ones listed (as many as fit
+reasonably) on the actual cover, and continue the rest onto adjacent
+pages.
+
+If you publish or distribute Opaque copies of the Document numbering
+more than 100, you must either include a machine-readable Transparent
+copy along with each Opaque copy, or state in or with each Opaque copy
+a computer-network location from which the general network-using
+public has access to download using public-standard network protocols
+a complete Transparent copy of the Document, free of added material.
+If you use the latter option, you must take reasonably prudent steps,
+when you begin distribution of Opaque copies in quantity, to ensure
+that this Transparent copy will remain thus accessible at the stated
+location until at least one year after the last time you distribute an
+Opaque copy (directly or through your agents or retailers) of that
+edition to the public.
+
+It is requested, but not required, that you contact the authors of the
+Document well before redistributing any large number of copies, to give
+them a chance to provide you with an updated version of the Document.
+
+@item
+MODIFICATIONS
+
+You may copy and distribute a Modified Version of the Document under
+the conditions of sections 2 and 3 above, provided that you release
+the Modified Version under precisely this License, with the Modified
+Version filling the role of the Document, thus licensing distribution
+and modification of the Modified Version to whoever possesses a copy
+of it. In addition, you must do these things in the Modified Version:
+
+@enumerate A
+@item
+Use in the Title Page (and on the covers, if any) a title distinct
+from that of the Document, and from those of previous versions
+(which should, if there were any, be listed in the History section
+of the Document). You may use the same title as a previous version
+if the original publisher of that version gives permission.
+
+@item
+List on the Title Page, as authors, one or more persons or entities
+responsible for authorship of the modifications in the Modified
+Version, together with at least five of the principal authors of the
+Document (all of its principal authors, if it has fewer than five),
+unless they release you from this requirement.
+
+@item
+State on the Title page the name of the publisher of the
+Modified Version, as the publisher.
+
+@item
+Preserve all the copyright notices of the Document.
+
+@item
+Add an appropriate copyright notice for your modifications
+adjacent to the other copyright notices.
+
+@item
+Include, immediately after the copyright notices, a license notice
+giving the public permission to use the Modified Version under the
+terms of this License, in the form shown in the Addendum below.
+
+@item
+Preserve in that license notice the full lists of Invariant Sections
+and required Cover Texts given in the Document's license notice.
+
+@item
+Include an unaltered copy of this License.
+
+@item
+Preserve the section Entitled ``History'', Preserve its Title, and add
+to it an item stating at least the title, year, new authors, and
+publisher of the Modified Version as given on the Title Page. If
+there is no section Entitled ``History'' in the Document, create one
+stating the title, year, authors, and publisher of the Document as
+given on its Title Page, then add an item describing the Modified
+Version as stated in the previous sentence.
+
+@item
+Preserve the network location, if any, given in the Document for
+public access to a Transparent copy of the Document, and likewise
+the network locations given in the Document for previous versions
+it was based on. These may be placed in the ``History'' section.
+You may omit a network location for a work that was published at
+least four years before the Document itself, or if the original
+publisher of the version it refers to gives permission.
+
+@item
+For any section Entitled ``Acknowledgements'' or ``Dedications'', Preserve
+the Title of the section, and preserve in the section all the
+substance and tone of each of the contributor acknowledgements and/or
+dedications given therein.
+
+@item
+Preserve all the Invariant Sections of the Document,
+unaltered in their text and in their titles. Section numbers
+or the equivalent are not considered part of the section titles.
+
+@item
+Delete any section Entitled ``Endorsements''. Such a section
+may not be included in the Modified Version.
+
+@item
+Do not retitle any existing section to be Entitled ``Endorsements'' or
+to conflict in title with any Invariant Section.
+
+@item
+Preserve any Warranty Disclaimers.
+@end enumerate
+
+If the Modified Version includes new front-matter sections or
+appendices that qualify as Secondary Sections and contain no material
+copied from the Document, you may at your option designate some or all
+of these sections as invariant. To do this, add their titles to the
+list of Invariant Sections in the Modified Version's license notice.
+These titles must be distinct from any other section titles.
+
+You may add a section Entitled ``Endorsements'', provided it contains
+nothing but endorsements of your Modified Version by various
+parties---for example, statements of peer review or that the text has
+been approved by an organization as the authoritative definition of a
+standard.
+
+You may add a passage of up to five words as a Front-Cover Text, and a
+passage of up to 25 words as a Back-Cover Text, to the end of the list
+of Cover Texts in the Modified Version. Only one passage of
+Front-Cover Text and one of Back-Cover Text may be added by (or
+through arrangements made by) any one entity. If the Document already
+includes a cover text for the same cover, previously added by you or
+by arrangement made by the same entity you are acting on behalf of,
+you may not add another; but you may replace the old one, on explicit
+permission from the previous publisher that added the old one.
+
+The author(s) and publisher(s) of the Document do not by this License
+give permission to use their names for publicity for or to assert or
+imply endorsement of any Modified Version.
+
+@item
+COMBINING DOCUMENTS
+
+You may combine the Document with other documents released under this
+License, under the terms defined in section 4 above for modified
+versions, provided that you include in the combination all of the
+Invariant Sections of all of the original documents, unmodified, and
+list them all as Invariant Sections of your combined work in its
+license notice, and that you preserve all their Warranty Disclaimers.
+
+The combined work need only contain one copy of this License, and
+multiple identical Invariant Sections may be replaced with a single
+copy. If there are multiple Invariant Sections with the same name but
+different contents, make the title of each such section unique by
+adding at the end of it, in parentheses, the name of the original
+author or publisher of that section if known, or else a unique number.
+Make the same adjustment to the section titles in the list of
+Invariant Sections in the license notice of the combined work.
+
+In the combination, you must combine any sections Entitled ``History''
+in the various original documents, forming one section Entitled
+``History''; likewise combine any sections Entitled ``Acknowledgements'',
+and any sections Entitled ``Dedications''. You must delete all
+sections Entitled ``Endorsements.''
+
+@item
+COLLECTIONS OF DOCUMENTS
+
+You may make a collection consisting of the Document and other documents
+released under this License, and replace the individual copies of this
+License in the various documents with a single copy that is included in
+the collection, provided that you follow the rules of this License for
+verbatim copying of each of the documents in all other respects.
+
+You may extract a single document from such a collection, and distribute
+it individually under this License, provided you insert a copy of this
+License into the extracted document, and follow this License in all
+other respects regarding verbatim copying of that document.
+
+@item
+AGGREGATION WITH INDEPENDENT WORKS
+
+A compilation of the Document or its derivatives with other separate
+and independent documents or works, in or on a volume of a storage or
+distribution medium, is called an ``aggregate'' if the copyright
+resulting from the compilation is not used to limit the legal rights
+of the compilation's users beyond what the individual works permit.
+When the Document is included in an aggregate, this License does not
+apply to the other works in the aggregate which are not themselves
+derivative works of the Document.
+
+If the Cover Text requirement of section 3 is applicable to these
+copies of the Document, then if the Document is less than one half of
+the entire aggregate, the Document's Cover Texts may be placed on
+covers that bracket the Document within the aggregate, or the
+electronic equivalent of covers if the Document is in electronic form.
+Otherwise they must appear on printed covers that bracket the whole
+aggregate.
+
+@item
+TRANSLATION
+
+Translation is considered a kind of modification, so you may
+distribute translations of the Document under the terms of section 4.
+Replacing Invariant Sections with translations requires special
+permission from their copyright holders, but you may include
+translations of some or all Invariant Sections in addition to the
+original versions of these Invariant Sections. You may include a
+translation of this License, and all the license notices in the
+Document, and any Warranty Disclaimers, provided that you also include
+the original English version of this License and the original versions
+of those notices and disclaimers. In case of a disagreement between
+the translation and the original version of this License or a notice
+or disclaimer, the original version will prevail.
+
+If a section in the Document is Entitled ``Acknowledgements'',
+``Dedications'', or ``History'', the requirement (section 4) to Preserve
+its Title (section 1) will typically require changing the actual
+title.
+
+@item
+TERMINATION
+
+You may not copy, modify, sublicense, or distribute the Document
+except as expressly provided under this License. Any attempt
+otherwise to copy, modify, sublicense, or distribute it is void, and
+will automatically terminate your rights under this License.
+
+However, if you cease all violation of this License, then your license
+from a particular copyright holder is reinstated (a) provisionally,
+unless and until the copyright holder explicitly and finally
+terminates your license, and (b) permanently, if the copyright holder
+fails to notify you of the violation by some reasonable means prior to
+60 days after the cessation.
+
+Moreover, your license from a particular copyright holder is
+reinstated permanently if the copyright holder notifies you of the
+violation by some reasonable means, this is the first time you have
+received notice of violation of this License (for any work) from that
+copyright holder, and you cure the violation prior to 30 days after
+your receipt of the notice.
+
+Termination of your rights under this section does not terminate the
+licenses of parties who have received copies or rights from you under
+this License. If your rights have been terminated and not permanently
+reinstated, receipt of a copy of some or all of the same material does
+not give you any rights to use it.
+
+@item
+FUTURE REVISIONS OF THIS LICENSE
+
+The Free Software Foundation may publish new, revised versions
+of the GNU Free Documentation License from time to time. Such new
+versions will be similar in spirit to the present version, but may
+differ in detail to address new problems or concerns. See
+@uref{https://www.gnu.org/licenses/}.
+
+Each version of the License is given a distinguishing version number.
+If the Document specifies that a particular numbered version of this
+License ``or any later version'' applies to it, you have the option of
+following the terms and conditions either of that specified version or
+of any later version that has been published (not as a draft) by the
+Free Software Foundation. If the Document does not specify a version
+number of this License, you may choose any version ever published (not
+as a draft) by the Free Software Foundation. If the Document
+specifies that a proxy can decide which future versions of this
+License can be used, that proxy's public statement of acceptance of a
+version permanently authorizes you to choose that version for the
+Document.
+
+@item
+RELICENSING
+
+``Massive Multiauthor Collaboration Site'' (or ``MMC Site'') means any
+World Wide Web server that publishes copyrightable works and also
+provides prominent facilities for anybody to edit those works. A
+public wiki that anybody can edit is an example of such a server. A
+``Massive Multiauthor Collaboration'' (or ``MMC'') contained in the
+site means any set of copyrightable works thus published on the MMC
+site.
+
+``CC-BY-SA'' means the Creative Commons Attribution-Share Alike 3.0
+license published by Creative Commons Corporation, a not-for-profit
+corporation with a principal place of business in San Francisco,
+California, as well as future copyleft versions of that license
+published by that same organization.
+
+``Incorporate'' means to publish or republish a Document, in whole or
+in part, as part of another Document.
+
+An MMC is ``eligible for relicensing'' if it is licensed under this
+License, and if all works that were first published under this License
+somewhere other than this MMC, and subsequently incorporated in whole
+or in part into the MMC, (1) had no cover texts or invariant sections,
+and (2) were thus incorporated prior to November 1, 2008.
+
+The operator of an MMC Site may republish an MMC contained in the site
+under CC-BY-SA on the same site at any time before August 1, 2009,
+provided the MMC is eligible for relicensing.
+
+@end enumerate
+
+@page
+@heading ADDENDUM: How to use this License for your documents
+
+To use this License in a document you have written, include a copy of
+the License in the document and put the following copyright and
+license notices just after the title page:
+
+@smallexample
+@group
+ Copyright (C) @var{year} @var{your name}.
+ Permission is granted to copy, distribute and/or modify this document
+ under the terms of the GNU Free Documentation License, Version 1.3
+ or any later version published by the Free Software Foundation;
+ with no Invariant Sections, no Front-Cover Texts, and no Back-Cover
+ Texts. A copy of the license is included in the section entitled ``GNU
+ Free Documentation License''.
+@end group
+@end smallexample
+
+If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts,
+replace the ``with@dots{}Texts.''@: line with this:
+
+@smallexample
+@group
+ with the Invariant Sections being @var{list their titles}, with
+ the Front-Cover Texts being @var{list}, and with the Back-Cover Texts
+ being @var{list}.
+@end group
+@end smallexample
+
+If you have Invariant Sections without Cover Texts, or some other
+combination of the three, merge those two alternatives to suit the
+situation.
+
+If your document contains nontrivial examples of program code, we
+recommend releasing these examples in parallel under your choice of
+free software license, such as the GNU General Public License,
+to permit their use in free software.
+
+@c Local Variables:
+@c ispell-local-pdict: "ispell-dict"
+@c End:
diff --git a/scanner.texi b/scanner.texi
new file mode 100644
index 0000000000..d99c9080ae
--- /dev/null
+++ b/scanner.texi
@@ -0,0 +1,481 @@
+\input texinfo @c -*-texinfo-*-
+@c %**start of header
+@setfilename scanner.info
+@c try the time-stamp package for version stuff
+@set VERSION 0.3
+@settitle Scanner Manual @value{VERSION}
+@syncodeindex vr cp
+@syncodeindex fn cp
+@documentencoding UTF-8
+@c %**end of header
+@copying
+This is the @emph{Scanner Manual}, corresponding to version @value{VERSION}.
+
+Copyright @copyright{} 2021 Free Software Foundation, Inc.
+
+@quotation
+Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.3
+or any later version published by the Free Software Foundation;
+with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
+A copy of the license is included in the section entitled ``GNU
+Free Documentation License''.
+
+A copy of the license is also available from the Free Software
+Foundation Web site at @url{https://www.gnu.org/licenses/fdl.html}.
+
+@end quotation
+
+The document was typeset with
+@uref{http://www.texinfo.org/, GNU Texinfo}.
+
+@end copying
+
+@dircategory Emacs
+@direntry
+* Scanner: (scanner)Document and image scanning in GNU Emacs
+@end direntry
+
+
+@titlepage
+@title Scanner
+@subtitle Document and image scanning in GNU Emacs, version @value{VERSION}
+@author Raffael Stocker
+@page
+@vskip 0pt plus 1filll
+@insertcopying
+@end titlepage
+
+@c Output the table of the contents at the beginning.
+@contents
+
+@ifnottex
+@node Top
+@top Scanner
+
+
+@insertcopying
+@end ifnottex
+
+@c Generate the nodes for this menu with `C-c C-u C-a'.
+@menu
+* Overview::
+* User Options::
+* Improving Scan Quality::
+* Reporting Bugs::
+* Hacking::
+* GNU Free Documentation License::
+* Index::
+@end menu
+
+@c Update all node entries with `C-c C-u C-n'.
+@c Insert new nodes with `C-c C-c n'.
+@node Overview
+@chapter Overview
+@cindex Overview
+
+@menu
+* Introduction::
+* Principle of Operation::
+* Basic Setup::
+* Scanning Documents::
+* Scanning Images::
+@end menu
+
+@node Introduction
+@section Introduction
+@cindex Introduction
+
+If you want to scan a document at high quality with @acronym{OCR,
+optical character recognition} and not use one of the available free
+GUI programs, there are several things you might have to do:
+@itemize
+
+@item
+use a program like @command{scanimage} to obtain an image file from
+your scanner,
+
+@item
+enhance the image quality using a post-processing tool like
+@command{unpaper}, and
+
+@item
+generate a PDF or text file with OCR software like @command{tesseract}.
+@end itemize
+
+Although this is not difficult to do in principle, each of these
+programs requires an elaborate incantation to produce adequate output:
+@itemize
+
+@item
+the scan resolution must be set to something appropriate for later OCR
+(usually 300 to 600 dpi,)
+
+@item
+the page size must be defined,
+
+@item
+perhaps some offsets must be added to page borders,
+
+@item
+the document may have to be rotated,
+
+@item
+some scan artifacts, like shadows, may have to be removed,
+
+@item
+the page may need deskewing,
+
+@item
+the language for OCR must be selected,
+
+@item
+@dots{}
+@end itemize
+
+Luckily, many of these items change rarely or not at all. Scanner
+uses the customization system of GNU Emacs
+(@pxref{Customization,,,emacs,The GNU Emacs Manual}) to remember the
+necessary settings and takes care of processing using the
+abovementioned programs.
+
+
+@node Principle of Operation
+@section Principle of Operation
+@cindex principle of operation
+@cindex operation, principle of
+
+@c sequence of program calls
+@c use of temporary files
+@c re-entrancy (but maybe mangled log)
+@c log buffer for diagnosis
+@c data and configuration files/directories needed by the programs
+@c use of more than one device: select new device between scans
+
+
+@node Basic Setup
+@section Basic Setup
+@cindex basic setup
+@cindex setup, basic
+@cindex configuration, basic
+@cindex installation
+
+Basic setup items:
+- program executables
+- paper/image size
+- nothing with unpaper
+- file formats and outputs
+
+Just name the important items, refer to the detailed chapter for more
+information.
+
+@node Scanning Documents
+@section Scanning Documents
+@cindex scanning documents
+@cindex documents, scanning
+
+describe functions for document scanning
+refer also to menu entries
+
+
+@table @kbd
+@item M-x scanner-scan-document
+Scan a document.
+@end table
+
+@node Scanning Images
+@section Scanning Images
+@cindex scanning images
+@cindex images, scanning
+
+describe functions for image scanning
+
+@anchor{scanner-scan-image}
+@defun scanner-scan-image nscans filename
+@end defun
+
+
+
+@node User Options
+@chapter User Options
+@cindex user options
+
+This chapter lists all the available user options. All of these
+options can be edited using the customization system of GNU Emacs,
+which is advisable as then basic sanity checks are carried out. For a
+number of options, interactive commands are available that simplify
+the customization at run time, but don't save the changed values
+between Emacs sessions. These functions are also available from the
+Scanner menu (@clicksequence{Tools @click{} Scanner}).
+
+@menu
+* General Options::
+* Options for scanimage::
+* Options for unpaper::
+* Options for tesseract::
+@end menu
+
+@node General Options
+@section General Options
+@cindex general options
+
+@table @kbd
+@item M-x scanner-set-image-resolution
+@item M-x scanner-set-document-resolution
+These commands interactively ask for a resolution (in @acronym{DPI,
+dots per inch}) to be used in subsequent image and document scans,
+respectively. Note that these commands set @code{scanner-resolution}
+directly, but don't change the saved customization value, that is, a
+resolution set with these commands will not be remembered between
+Emacs sessions.
+
+These commands are available in the Scanner menu as@*
+@clicksequence{Tools @click{} Scanner @click{} Select image
+resolution}@*
+and@*
+@clicksequence{Tools @click{} Scanner @click{} Select
+document resolution}
+
+@item M-x scanner-select-papersize
+
+@item M-x scanner-select-device
+Select a device, possibly triggering auto-detection.
+
+@item C-u M-x scanner-select-device
+Select a device, forcing auto-detection.
+@end table
+
+
+
+@defopt scanner-resolution
+This option specifies the resolution in DPI used for image and
+document scans as a property list with the keys @code{:image} and
+@code{:doc}, respectively, and integers as values. The default is:
+@lisp
+(:image 600 :doc 300)
+@end lisp
+The available resolutions depend on your device.
+@end defopt
+
+@defopt scanner-paper-sizes
+@end defopt
+
+@defopt scanner-doc-papersize
+@end defopt
+
+@defopt scanner-image-size
+This option specifies the size used in image scans as a list of width
+and height values in millimeters. The default is
+@lisp
+(200 250)
+@end lisp
+for an image of 200@dmn{mm} width and 250@dmn{mm} height. If set to
+nil, the size is determined by scanimage (usually the available scan
+area.)
+@end defopt
+
+@deffn {Interactive Command} scanner-select-image-size x y
+@end deffn
+
+@defopt scanner-scan-delay
+This option specifies the delay in seconds to wait between pages in a
+multi-page scan. Set this to something large enough so you can feed
+the next sheet to your scanner before it starts scanning the next
+page. The default is 3.
+@end defopt
+
+@defopt scanner-device-name
+The device name of the scanner as reported by scanimage. The default
+is nil, which prompts Scanner to use scanimage for automatic
+detection. The detected device will be stored in this variable and
+used for all subsequent scans, until a new detection is forced either
+by calling @code{scanner-select-device} with a prefix argument, or by
+this device becoming unavailable.
+
+Usually you need not customize this option as auto-detection should
+work just fine.
+@end defopt
+
+@defopt scanner-reverse-pages
+This option, when set to t, causes Scanner to reverse the order of the
+scanned pages in a document scan. The default is nil.
+@end defopt
+
+@node Options for scanimage
+@section Options for scanimage
+@cindex options for scanimage
+
+Some of the options scanimage accepts (and Scanner uses) are
+device-dependent. These options are marked as @emph{device-dependent}
+in their definitions. To find out which options your scanner hardware
+offers, run @command{scanimage --help} with your scanner plugged in.
+This incantation should print a list of general and device-dependent
+options.
+
+@defopt scanner-scanimage-program
+This option specifies the path of scanimage. The default is given by
+@lisp
+(executable-find "scanimage")
+@end lisp
+@end defopt
+
+@defopt scanner-scan-mode
+@emph{Device-dependent}@*
+This option specifies the scan modes for document and image scans. It
+is a property list with the keys @code{:image} and @code{:doc}, for
+images and documents, respectively, and strings naming the scan modes
+as values. For example,
+@lisp
+(:image "Color" :doc "Gray")
+@end lisp
+sets ``Color'' mode for image scans and ``Gray'' mode for document
+scans. The default is to use ``Color'' for both image and document
+scans.
+
+The available scan modes depend on your device. Usually, ``Lineart'',
+``Gray'', and ``Color'' are available. For images you probably want
+``Color'', and for good OCR results in document scans, you should
+choose either ``Gray'' or ``Color''.
+@end defopt
+
+@defopt scanner-image-format
+This option sets the default format used by scanimage for image and
+document scans. It is a property list similar to
+@var{scanner-scan-mode}. For example, the default
+@lisp
+(:image "jpeg" :doc "pnm")
+@end lisp
+configures Scanner to use the JPEG format for image scans and the PNM
+format for document scans. While document scans will always use the
+format specified with this option, you can override the format used in
+image scans with the appropriate file extension, see
+@ref{scanner-scan-image}.
+
+The supported formats are documented in the scanimage manual page.
+For example, version 1.0.31 of scanimage supports PNM, TIFF, PNG and
+JPEG.
+
+Note that the document scan format specified with this option is an
+intermediate format, not the document format generated at the end of
+the whole process. With the PNM format used in the example above, you
+can still have a PDF output, see @ref{scanner-tesseract-outputs}.
+
+If you use unpaper for post-processing before OCR in document scans,
+the format will silently be forced to PNM, as this is required by
+unpaper.
+@end defopt
+
+@defopt scanner-scanimage-switches
+You may find that additional switches to scanimage not covered by any
+of the above user options are necessary. You can use
+@var{scanner-scanimage-switches} for these. Specify the switches as a
+list of switch/value pairs, such as:
+@lisp
+("--switch1" "value1" "-s" "2")
+@end lisp
+The default is nil.
+
+For example, some devices may need some tweaking of brightness and
+contrast to provide adequate scans. Something like
+@lisp
+("--brightness" "20" "--contrast" "50")
+@end lisp
+might do the trick. Note, however, that the switches in this example
+are device-dependent.
+@end defopt
+
+
+@node Options for unpaper
+@section Options for unpaper
+@cindex options for unpaper
+
+@defopt scanner-unpaper-program
+@end defopt
+
+@defopt scanner-use-unpaper
+@end defopt
+
+@defopt scanner-unpaper-page-layout
+@end defopt
+
+@defopt scanner-unpaper-input-pages
+@end defopt
+
+@defopt scanner-unpaper-output-pages
+@end defopt
+
+@defopt scanner-unpaper-pre-rotation
+@end defopt
+
+@defopt scanner-unpaper-post-rotation
+@end defopt
+
+@defopt scanner-unpaper-pre-size
+@end defopt
+
+@defopt scanner-unpaper-post-size
+@end defopt
+
+@defopt scanner-unpaper-border
+@end defopt
+
+@defopt scanner-unpaper-switches
+@end defopt
+
+@node Options for tesseract
+@section Options for tesseract
+@cindex options for tesseract
+
+@defopt scanner-tessdata-dir
+@end defopt
+
+@defopt scanner-tesseract-configdir
+@end defopt
+
+@defopt scanner-tesseract-languages
+@end defopt
+
+@anchor{scanner-tesseract-outputs}
+@defopt scanner-tesseract-outputs
+@end defopt
+
+@defopt scanner-tesseract-switches
+@end defopt
+
+@node Improving Scan Quality
+@chapter Improving Scan Quality
+@cindex improving scan quality
+@cindex scan quality, improving
+@cindex quality, improving
+
+include tips for improving quality, ask for contributions
+
+
+
+@node Reporting Bugs
+@chapter Reporting Bugs
+
+Refer to @uref{https://www.gitlab.com/rstocker/scanner/}
+mention *Scanner* log buffer
+
+@node Hacking
+@chapter Hacking
+
+document internal functions and how they are used?
+
+@node GNU Free Documentation License
+@chapter GNU Free Documentation License
+@c Get fdl.texi from https://www.gnu.org/licenses/fdl.html
+@include fdl.texi
+
+
+@node Index
+@unnumbered Index
+
+@printindex cp
+
+@c combine indices
+
+@bye
+
+@c scanner.texi ends here
