View source for Help:Image-Annotator

{{header|Lang-ImageAnnotatorHelp}}
[[Category:ImageAnnotator]]
<div style="float:right; border:1px solid #8888aa; background:#fff8cc; padding:0.2em;">
The Commons is running
:'''Version 2.3b'''
of this gadget.
</div>

[[MediaWiki:Gadget-ImageAnnotator.js|ImageAnnotator]] is a gadget that allows users to place comments ''onto'' images shown on file description pages, similar to the "photo notes" on [[wikipedia:Flickr|Flickr]]. It works on all image files for which the MediaWiki software displays a preview image on the file description page, i.e., PNG, JPG, GIF, SVG, and single-page TIFF files.

== Trying it out ==

If you want to make test edits using this feature but don't want to do so on live pages, you can create here a personal "sandbox" page in your user space where you can play around as you like. Just click the button below, and then save the page you're being taken to.
{{#tag: inputbox|
type=create
buttonlabel=Create personal image note sandbox
default=Special:Mypage/imagenote-sandbox
preload=Template:ImageAnnotatorSandbox
editintro=Template:ImageAnnotatorSandboxEditIntro
hidden=yes
}}

Please note that here at the commons, image notes are configured such that only [[Commons:Autoconfirmed users|autoconfirmed users]] can modify (edit/add/delete) image notes. Other users can edit image notes only within their own user space, such as on their personal image note sandboxes.

== How to add informative notes ==
''See [[Commons:Using ImageAnnotator]] guidelines.''

Image annotations in general should highlight features, details, or points of interest ''within'' an image. A description of the image ''as a whole'' is better placed on the image description page directly (click the "edit" link at the top of the page to do so).

In general, images that can benefit most from annotations are ''busy'' images like: group portraits, panoramas, aerial photographs, satellite images, maps and diagrams. The type of images that likely will not be improved by notes are ''simple'' images lacking enough detail to need notes. For example: flags, coats of arms, computer icons, single person portraits, etc. Of course one can find many exceptions from this general rule. The content of a note should be relevant to the region of the image outlined by its box and as with other descriptions, "neutrality of description should be aimed at wherever possible" (see [[COM:NPOV]]). Use of links to Commons categories, Commons galleries, or Wikipedia articles is encouraged.

== User interface ==

On image description pages, the script adds a button "Add a note" below the preview image. If the image already has annotations, it also shows a message indicating such. The button is only present if Ajax is enabled.

=== Display of image annotations ===

An annotation is shown on the preview image as a yellow rectangle. The note is supposed to explain some feature in the image at the location of that rectangle. These yellow rectangles are only shown if the user moves the mouse cursor over the preview image, otherwise they're hidden.

If the yellow rectangles are visible, the note text will appear in a small popup when the user moves the mouse cursor over such a rectangle. This popup is hidden again when the mouse leaves the area of the rectangle combined with the area of the popup. While the popup is visible, its rectangle will be highlighted.

{|class="wikitable"
!Screenshot||Explanation
|-
|[[File:ImageAnnotator_Normal.jpg|300px]]||Initial display: rectangles are invisible because the mouse pointer is outside the image. Text below the image indicates the presence of annotations, and there's a button to add new notes.
|-
|[[File:ImageAnnotator_Rectangles.jpg|300px]]||When the mouse pointer is moved onto the image, the rectangles are shown.
|-
|[[File:ImageAnnotator_Note.jpg|300px]]||When the mouse pointer is moved over the rectangles, the corresponding notes are shown...
|-
|[[File:ImageAnnotator_Note2.jpg|300px]]||... and the rectangles are highlighted.
|}

=== Adding a new annotation ===

When the "Add a note" button is clicked, the script enters definition mode. The preview image gets a green border, and the rectangles of all existing notes are shown. The user can now draw a new rectangle (shown in red) onto the preview image by clicking within the image, dragging the mouse cursor, and then releasing the mouse cursor. If the resulting rectangle has non-zero width and height, the note editor will pop up. When the note text is saved from that editor, a new note will be placed onto the preview image.

If the full image is much larger than the preview image, the script provides a floating zoom to make it easier to position the new rectangle. By default, this zoom is activated when the full image size is eight times larger than the preview, but this can be [[#Setting the zoom activation|configured]] by the user to their liking. The zoomed image is initially just the preview image scaled up by the browser, but the script loads an image at the correct zoomed size from the server in the background, and once that truly zoomed image has arrived, it replaces the browser's upscaled image.

{|class="wikitable"
!Screenshot||Explanation
|-
|[[File:ImageAnnotator_Button.jpg|102x36px]]||This is the button to add a new note. It is located below the preview image on the image description page.
|-
|[[File:ImageAnnotator_Draw0.jpg|300px]]||The image has a green border, and the rectangles of all existing annotations are shown.
|-
|[[File:ImageAnnotator_DrawZoom.jpg|300px]]||Because this is a huge file, ImageAnnotator provides a built-in zoom as soon as the mouse pointer enters the image.
|-
|[[File:ImageAnnotator_DrawRect.jpg|300px]]||The new rectangle is shown in red. Once the left mouse button is released within the image, the editor will be shown.
|-
|[[File:ImageAnnotator_Editor.jpg|300px]]||If Ajax is enabled, notes can be edited. The note editor appears in a popup in the vicinity of the note's yellow rectangle, and is pre-filled with the current text of the note (or empty, if the user is editing a newly defined note). The editor of ImageAnnotator features a built-in preview. The text entered may contain WikiText markup.
|}

=== Editing a note ===

The note editor fully supports a preview function, just like the standard edit pages. Clearing the text and saving will delete an existing note (or cancel the definition of a new note). The "Revert" button will discard all changes made by the user and fill the editor again with the current text of the note. The "Cancel" button will close the editor without applying the changes. Clicking the "Save" button will edit the current page in the background and add the note text plus the coordinates of its rectangle to the page.

=== Deleting a note ===

An existing note can be deleted in two ways:
* by clicking the "Delete" link in the note's popup, or
* by editing it, clearing the text, and then saving.
When you remove a note through ''ImageAnnotator'', it will prompt you for a deletion reason.

=== User rights ===

The ability to edit, add, or delete notes is available only on pages the user is actually allowed to edit. On protected pages, non-admin users can only view existing notes. On files stored non-locally, only viewing of notes is possible.

Please note that here at the commons, image notes are configured so that only [[Commons:Autoconfirmed users|autoconfirmed users]] can modify (edit/add/delete) image notes. Other users can edit image notes only within their own user space, such as on their personal image note sandboxes.

{{anchor|LOCALA}}

== Local annotations ==

Normally, the gadget is used on file description pages. On such pages, it is activated automatically.

Sometimes, one might use image notes for an image on other pages, though. An example is [[COM:FPC|nominations for featured pictures]], where notes that are local to the nomination, but that are not shown on the file description pages, could be used to point out problems in an image.

This is possible through the use of template {{tl|ImageWithNotes}}. Any file link that actually displays an image that is wrapped with a '''''substitution''''' of that template also activates the gadget. Notes added for such images are stored on the page that includes the substitution of the {{tl|ImageWithNotes}} template, not on the file description page.

If a page contains more than one substitution of {{tl|ImageWithNotes}}, either directly or though transclusions, as on [[COM:FPC]], the gadget only allows viewing notes. Editing notes is possible only on the page that directly contains the template substitution. A nomination page that uses this feature is [[Commons:Featured picture candidates/File:Vista panorámica de Peñíscola desde el castillo.jpg]].

This mechanism is also used on the [[#Trying it out|personal image note sandbox pages]].

== Inline display of annotations ==

[[File:Spelterini Blüemlisalp.jpg|thumb|This image has a few notes, which you should be able to see here on this thumbnail if version 2 of ImageAnnotator is enabled.]]

Since version 2, ImageAnnotator can also display notes defined on an image description page on the thumbnails of that image where it is used in articles, both at the same and at other projects (if those other projects also have version 2 of ImageAnnotator installed). This feature is highly configurable. ImageAnnotator can be configured on a site-wide basis
*whether to display notes on such thumbnails at all, depending on whether the image is local and the namespace of the page on which the thumbnail appears, and depending on whether the use is actually a thumbnail (<code><nowiki>[[File:Example.jpg|thumb|...]]</nowiki></code>) or an ''inline image'' (without the "thumbnail", i.e., <code><nowiki>[[File:Example.jpg|...]]</nowiki></code>). See [[#Site-wide configuration|site-wide configuration]] below.
*whether to display the full notes (rectangles and popups) or just a small icon indicating that there are additional notes.
In addition, template {{tl|InlineImageAnnotations}} can be used to define note display on thumbnails and inline images on a per-image basis. This template is placed on the image description page of an image that has notes and defines how notes are displayed in places where that image is used. See the template for documentation.

Furthermore, note display on images in articles can ''also'' be defined on a per-article basis by placing the template {{tl|ImageAnnotations}} in the article.

If both are used, the values from the per-image definition (in the {{tl|InlineImageAnnotations}} on the image description page) have an effect only if there is no definition in the {{tl|ImageAnnotations}} on the article page. Otherwise, the per-article definition overrides the per-image definition.

Users can additionally switch off note display on inline images and thumbnails on a per-namespace basis. See [[#User configurations]] below.

In galleries (created with the &lt;gallery> markup), inline display of image annotations is always disabled.

== Rectangle colors ==

[[File:Prequile lyon 1863.jpg|thumb|On this image, rectangle colors have been changed from the default to make them more visible. Because the image has many notes, you may not see the notes here (depending on the [[#Site-wide configuration|configuration]]), but then you should see a small indication icon in the upper right or left corner of the image. Click on the image (or on the icon) to visit the file page, where you can then see the notes.]]
Normally, ''ImageAnnotator'' displays the rectangles of notes with yellow borders, and highlights the rectangle of the currently visible note using an orange color. On images that are predominantly yellowish or in orange tones, this makes the rectangles hard to see. For such cases,
the rectangle colors can be specified on a per-image basis by adding the template {{tl|ImageNoteColors}} to the image description page.

A note rectangle has two borders, an outer and an inner border. To highlight the active rectangle (the one whose note is shown), the color of the outer border is set to the active color. All three colors can be specified with the template {{tl|ImageNoteColors}}. See the template for usage instructions.

The image at the right uses red rectangles, which work well in this case. They were generated by placing <code><nowiki>{{ImageNoteColors|inner=red}}</nowiki></code> on the file description page at [[:File:Prequile lyon 1863.jpg]].

On another yellowish image, [[:File:Schleswig Braun-Hogenberg.jpg]], red didn't work that well. It was better than yellow, but it turns out that using light green using <code><nowiki>{{ImageNoteColors|inner=#00FF00|active=#00FF00}}</nowiki></code> makes the note rectangles even more visible in this case.

In general, the "active" color, which is used to mark the rectangle of the currently visible note, should be a light color. Dark colors do not contrast enough with the default outer color (which is gray).

== Settings for a particular image use ==

<span style="border:1px solid #8888aa; background:#fff8cc; padding:0.2em;">as of Version 2.1</span>

Sometimes, one may want to control the appearance of image annotations for a single particular image use (thumbnail or otherwise included image) in an article. This can be accomplished by wrapping the image inclusion (the <code><nowiki>[[File:....|...]]</nowiki></code>) within template {{tl|ImageNoteControl}}. This template accepts parameters to
* switch off image annotation for a particular image use altogether,
* show only an indication icon instead of the notes and a caption indicating their presence, or
* display the notes but suppress this caption.

See the [[Template:ImageNoteControl|template]] itself for more information.

== Site-wide configuration ==

Site-wide configuration of ImageAnnotator is done in file [[MediaWiki:ImageAnnotatorConfig.js]]. This is a JavaScript file, so any changes there should be made only by admins who do know the JavaScript programming language. This is even more important as changes in that file start taking effect immediately. (The file is cached by clients for four hours, so after four hours a change in the site-wide configuration will have propagated to everybody.)

The site-wide configuration overrides any definitions from {{tl|ImageAnnotations}} in articles or from {{tl|InlineImageAnnotations}} on image description pages.

In [[MediaWiki:ImageAnnotatorConfig.js]], admins can define:
* where image annotations should be displayed at all: <code>viewingEnabled()</code>
* who (everyone, or autoconfirmed users only, or other rules) may edit image annotations (if viewing is enabled at all): <code>editingEnabled()</code>
* <span style="border:1px solid #8888aa; background:#fff8cc; padding:0.2em;">as of Version 2.2</span> who may remove image annotations through the gadget, and if so, whether empty deletion resons are allowed and who, if anybody, may bypass the prompt for a deletion reason altogether. (Note that image annotations may be removed anyway through normal edits to the image description page.) See <code>mayDelete()</code>, <code>emptyDeletionReasonAllowed()</code>, and <code>mayBypassDeletionPrompt()</code>.
* whether notes shall be shown on thumbnails (if viewing is enabled at all): <code>thumbsEnabled()</code>
* whether notes shall be shown on inline images, i.e., any non-thumbnail use of images (if viewing is enabled at all): <code>generalImagesEnabled()</code>
* whether notes shall be shown on image uses (thumbnail or other) for non-local images: <code>sharedImagesEnabled()</code>
* on which image uses to display rectangles and popups, and on which to use only an indicator icon (provided viewing is enabled at all): <code>inlineImageUsesIndicator()</code>
* <span style="border:1px solid #8888aa; background:#fff8cc; padding:0.2em;">as of Version 2.1</span> whether to display a caption on images with notes that are displayed in articles: <code>displayCaptionInArticles()</code>
* internal functions for determining the location of a shared repository (by default, the Commons; see <code>sharedRepositoryAPI()</code> and <code>imageIsFromSharedRepository()</code>), the default colors for note rectangles, and the default interface texts.
* <span style="border:1px solid #8888aa; background:#fff8cc; padding:0.2em;">as of Version 2.1</span> internal setting telling the gadget whether the wiki is set up to automatically generate missing thumbnails (<code>thumbnailsGeneratedAutomatically()</code>).
* <span style="border:1px solid #8888aa; background:#fff8cc; padding:0.2em;">as of Version 2.2</span> the default zoom activation threshold.

All these configurations cannot be overridden by a user and apply globally on the whole site. The default settings are to enable note display everywhere except on the main page, allow editing for everyone, display notes on any image uses, and to use an indicator icon on image uses if the image is either non-local (comes from the shared repository) or otherwise small and has more than six notes.

== User configurations ==

Users can customize some few aspects of ImageAnnotator.

=== Setting the edit box width ===

By default, ImageAnnotator uses a textbox for modifying notes that is 50 characters wide. Although notes may contain arbitrary WikiText, they should typically be rather short. The somewhat small edit box helps avoid that people write whole sermons in a note. If you often create notes containing long links, though, you might want a slightly larger box. In that case you can define the text box width by adding the following line to your [[Special:Mypage/monobook.js|monobook.js]] or other skin-specific JS file (such as [[Special:Mypage/vector.js|vector.js]] for the Vector skin):

<div style="overflow:auto; border:1px solid #8888aa; padding:0.3em; margin-top:0.5em; margin-bottom:0.5em; margin-left:2em;">
<syntaxhighlight lang="javascript">
var ImageAnnotationEditor_columns = 80; // Or any other number from 30 to 100.
</syntaxhighlight>
</div>

This specifies the width of the textbox in characters. If the value set is not a number or outside the range of 30 to 100, the gadget reverts to its default behavior and uses a box 50 characters wide.

<small>Note that on some browsers, notably Firefox, the textbox may be slightly wider than specified. Firefox, for instance, always adds space for a potential vertical scrollbar up front, even when it doesn't show a scrollbar yet. As a result, an empty textbox with 50 columns may on Firefox actually provide an input area that is 52 characters wide, until a vertical scrollbar appears.</small>

=== Setting the zoom activation ===

When the full image is much larger than the preview image, the script activates a floating zoom to make positioning new rectangles easier. How much larger the full image needs to be than the preview image to activate this zoom is governed by the ''zoom threshold''. By default, this threshold is set to 8.0: the zoom is activated only if the full image is eight times larger than the preview. This threshold ratio can be changed, though:

<div style="overflow:auto; border:1px solid #8888aa; padding:0.3em; margin-top:0.5em; margin-bottom:0.5em; margin-left:2em;">
<syntaxhighlight lang="javascript">
var ImageAnnotator_zoom_threshold = 8.0; // Or any other number >= 0
</syntaxhighlight>
</div>

Setting the threshold to very high values will in practice disable zooming for most images. Setting it to zero enables the zoom on all images where the full image is at least twice the size of the preview. (In other words, the lower bound of <code>ImageAnnotator_zoom_threshold</code> is 2.0 in practice.)

Whatever the setting of this variable, zooming is enabled automatically for users who have set a very small preview size in their preferences (smaller than 600 pixels wide), and for images that are more than twice as wide as high, but only if the full image is at least twice the size of the preview image.

=== Switching off note display on image uses ===

<span style="border:1px solid #8888aa; background:#fff8cc; padding:0.2em;">As of Version 2.0</span>

Logged-in users can customize note display on thumbnails and other images used in articles by setting special variables in their skin-specific user JS files, such as [[Special:Mypage/monobook.js|monobook.js]] for the "monobook" skin, or [[Special:Mypage/vector.js|vector.js]] for the "vector" skin.

This customization works on a per-namespace basis. For each feature, the user may define a list of namespace names for which the feature applies. Customizeable features are
*no_images : switch off note display on all image uses in the namespaces given
*no_thumbs : switch off note display only on thumbnails in the namespaces given
*no_shared : switch off note display for non-local images in the namespaces given
*icon_thumbs : use only an indicator icon (instead of showing the note rectangles and popups) for thumbnails in the namespaces given
*icon_images : use only an indicator icon for other (non-thumbnail) image uses in the namespaces given

These features are defined through variables the user declares in their skin-specific JS file. The variable names are <code>ImageAnnotator_no_images</code>, <code>ImageAnnotator_no_thumbs</code>, <code>ImageAnnotator_no_shared</code>, <code>ImageAnnotator_icon_thumbs</code>, and <code>ImageAnnotator_icon_images</code>. The values in all cases are JavaScript arrays of strings. An example of a user's configuration might be

<div style="margin-left:2em;padding:0.5em;border:1px solid #8888aa;overflow:auto;">
<syntaxhighlight lang="javascript">
var ImageAnnotator_no_images = ["Creator", "Creator talk"]; // No image note display on creator pages
var ImageAnnotator_no_thumbs = ["Talk"];                    // Don't show notes for thumbs on talk pages
var ImageAnnotator_icon_thumbs = ["Commons"];               // Only an indication icon for thumbs in the commons
                                                            // namespace, such as on [[COM:FPC]]
</syntaxhighlight>
</div>

<span style="border:1px solid #8888aa; background:#fff8cc; padding:0.2em;">as of Version 2.1</span> You may also use "*" as a wildcard denoting "any namespace" in these arrays.

<span style="border:1px solid #8888aa; background:#fff8cc; padding:0.2em;">as of Version 2.1</span> Using the variable <code>ImageAnnotator_hide_captions</code>, you can switch off the display of extra captions indicating the presence of annotations on image uses in articles. For instance,

<div style="margin-left:2em;padding:0.5em;border:1px solid #8888aa;overflow:auto;">
<syntaxhighlight lang="javascript">
var ImageAnnotator_hide_captions = ["*"];
</syntaxhighlight>
</div>

would suppress these captions on all image uses (thumbnails and otherwise included images) in all namespaces.

:<small>Note that this feature relies on the server including <code>wgNamespaceIds</code> in the inline JavaScript on the page. If <code>wgNamespaceIds</code> does not exist, this user-defined customization will not work. (But image annotations will continue to work anyway.)</small>

=== Switching off the prompt for a deletion reason ===

<span style="border:1px solid #8888aa; background:#fff8cc; padding:0.2em;">As of Version 2.2</span> If the [[#Site-wide configuration|site-wide configuration]] allows this at all, a user may switch off the prompt for a deletion reason when a note is removed through the gadget using

<div style="margin-left:2em;padding:0.5em;border:1px solid #8888aa;overflow:auto;">
<syntaxhighlight lang="javascript">
var ImageAnnotator_noDeletionPrompt = true;
</syntaxhighlight>
</div>

This setting is somewhat risky, though, because if a user may remove notes through the gadget (this is another site-wide configuration setting), the deletion link is just next to the edit link. With this setting, a single mis-click might inadvertently remove a note.

The default site-wide setting allows this only for administrators. There is another site-wide setting that determines whether empty deletion reasons are allowed; it's safer to use that to allow administrators quickly removing inappropriate notes.

== User interface texts ==

[[MediaWiki:Gadget-ImageAnnotator.js|ImageAnnotator]] uses a small number of texts in its user interface. If Ajax is enabled, the script loads localized strings for these interface messages.

These interface texts can be defined on-wiki in pages in the protected MediaWiki namespace, just like the standard interface texts of MediaWiki. The script uses the following interface texts:
<div style="margin-left:2em;padding:0.5em;border:1px solid #8888aa;">{{MediaWiki:ImageAnnotatorUITexts}}</div>

To localize these texts, just place the translations in subpages of these pages. The French texts, for instance, reside at "/fr" subpages:
<div style="margin-left:2em;padding:0.5em;border:1px solid #8888aa;">{{MediaWiki:ImageAnnotatorUITexts|lang=fr}}</div>

If there is no translation for a particular text, the script falls back to the English texts.

The help button is a bit special. [[MediaWiki:ImageAnnotatorHelp]] can be one of the following:
*A simple link, e.g. <code><nowiki>[[Help:Gadget-ImageAnnotator|Get help]]</nowiki></code>. This will insert the link as is.
*A span containing some simple text, followed by a link. This will insert a button with the text from the span, linking to the page given in the link.
*A sequence of one to three images, followed by a link. This will insert the image, linked to the page given in the link. If more than one image are given, the second is displayed when the mouse hovers over the resulting help button, and the third is displayed on a mouse click.
The third possibility is actually only useful if you really specify more than one image to create an animated button, or if you are running on an older MediaWiki installation that doesn't support the "link=" parameter for images. Otherwise, you can achieve the same effect (a clickable image linked to some page) by just defining [[MediaWiki:ImageAnnotatorHelp]] as e.g.
<pre><nowiki>
[[Image:Gtk-dialog-question-2.svg|16px|Help about image annotations|link=Help:Gadget-ImageAnnotator]]
</nowiki></pre>

The button labels are supposed to be simple texts. Those for the "Edit"/"Delete" links and for the "Preview", "Revert", and "Cancel" buttons are optional; if they're not defined, already existing MediaWiki messages that provide sensible default texts are used. Those for the "Save" and "Add a note" button do not have this fallback mechanism because there are no suitable pre-defined MediaWiki messages that could be used.

:<small>Getting the localizations through Ajax means that there will be one additional request to the servers for each and every image description page visited with [[MediaWiki:Gadget-ImageAnnotator.js|ImageAnnotator]] active. If this ever becomes a problem, one can either switch off localizations, or make the developers implement an image page footer system message that could be used to transport the interface strings on the page itself when it loads, like it was done for the upload form. However, thanks to caching in the browser and also in the Squids on the server side, this additional request should not be problematic. The only drawback is that localizations for [[MediaWiki:ImageAnnotatorHasNotesMsg]] are ignored if Ajax is switched off. On the other hand, the Ajax mechanism works without server-side changes.</small>

=== Edit summaries ===

In addition to the above interface texts, which can be fully localized, ''ImageAnnotator'' uses three more texts as edit summaries for the edits made through this script's interface. These texts are configurable, too, but they cannot be localized. The script uses these messages:
<div style="margin-left:2em;padding:0.5em;border:1px solid #8888aa;">{{MediaWiki:ImageAnnotatorEditSummaries}}</div>
These messages should be in the <code>wgContentLanguage</code> of the wiki (English at the English WMF projects and at the Commons; German at German projects, Arabic at Arabic projects, and so on). They should ''not'' be in the user's interface language. Edit summaries are targeted not at the editor making an edit, but are for the benefit of all other users at a wiki. Hence edit summaries should be in a language that most people working on a wiki understand, which is normally the content language of the wiki.

=== Translation pleas ===

Here at the Commons, the script adds small "translate"-links at various places in the interface if there are no interface texts in the user's language. Clicking such a link opens the page [[MediaWiki talk:ImageAnnotatorTexts]] for editing in preview mode; users can enter their translations and save them there so an administrator can later verify them and move them to the correct messages in the protected MediaWiki namespace.

== Browser compatibility ==

[[MediaWiki:Gadget-ImageAnnotator.js|ImageAnnotator]] has been tested and is known to work on the following browsers:

{{Help:Gadget-ImageAnnotator/Compatibility}}

Additionally, the script has been tested in the standard (classic), nostalgia, chick, cologneblue, modern, and vector skins using Firefox. It should work in all skins. It has also been tested accessing the Commons through the secure server (using Firefox).

The script has also been tested with RTL ("right-to-left") languages, here at the Commons using "uselang=he" (Hebrew) and also locally at the Arabic Wikipedia. Both tests were run using Firefox 3.0.11 and IE6.

Like for many other scripts at WikiMedia projects, a [http://www.w3.org/TR/DOM-Level-2-Core/core.html DOM Level 2] compatible browser is a prerequisite. Ajax is used to get [[#User interface texts|localized interface texts]], to save or delete notes, and for the preview feature of the note editor.

If JavaScript is disabled, the script will of course not do anything. If JavaScript is enabled but Ajax is disabled, the script still displays existing notes on the image, but the user cannot modify or delete them, and it's also not possible to add new notes.

Although modifying notes (automatically editing the image description page) works ''without'' the [[mw:API|MediaWiki API]], the API is used for previews and for getting [[#User interface texts|localized interface texts]]. On wikis where the API is disabled, the script may not work at all, or fail to show previews and localized interface texts. (The public WMF wikis, including the Wikipedias and the Commons, have the API enabled.) The script does ''not'' use the write API. Enabling the read API is sufficient.

== Installing ImageAnnotator on another Wiki ==

Image notes are only visible when the ImageAnnotator gadget is installed and activated (either by default for all users, or the viewing user has the gadget enabled). This means that notes added here at the Commons are not visible at other Wikis unless the gadget is installed there, too.

To install ImageAnnotator on a wiki, you need to be an administrator at that wiki. A [[Help:Gadget-ImageAnnotator/Installation|detailed installation guide]] is available.

== Limitations ==

*If an image that has annotations is overwritten by a new version, existing annotations are only displayed if the size of the full version of the top image matches the size of the full image on which the notes were defined. To recover annotations, one will need to edit the image description page manually, adjusting image sizes and rectangle coordinates, or re-enter annotations.

*Editing and deleting notes only works on modern browsers if the XHTML of the edit page is valid. Normally, this should not be a problem, but during alpha testing, people were updating [[MediaWiki:Copyrightwarning]], and sometimes that message generated invalid XHTML (improper nesting of tags, or spurious unclosed tags). When that happened, edits failed to save automatically.

== Frequently asked questions ==

#'''Can't image notes be stored on a subpage of the image page?'''
#:No, they cannot. This was considered as an option when this feature was developed, but the idea was given up because
#:#edits to notes wouldn't show up on watchlists unless people also watched these subpages (currently, editing notes generate edits to the image description page itself, so they show up on watchlists if the image is watched);
#:#it would be technically ''much'' harder to detect edit conflicts and keep things in sync between the notes displayed and the notes stored;
#:#the script would need to load the subpage just to display the notes, and we'd like to keep the number of calls to the server at a minimum; and
#:#it would be harder to keep things in sync if and when image moves are (re-)enabled.
#:Note that you CAN use local annotations on an image subpage.
#'''Can we have note regions with other shapes than rectangles?'''
#:No. JavaScript does not offer convenient drawing primitives. Rectangles are easy because HTML elements are all rectangular boxes, but anything else is either not possible at all in JavaScript or only with considerable difficulty using the &lt;canvas> element of HTML5, but HTML5 is not supported by older browsers, and back then our pages were "XHTML 1.0 transitional" anyway. Older versions of Internet Explorer (up to IE8) do not support &lt;canvas> out-of-the-box, though there are special extensions for it.
#'''Can we run the ImageAnnotator script in Wikipedias in order to see annotations there?'''
#:Yes, you can. Make a local administrator install the gadget, possibly lobby first to get consensus from your local wiki community. A good way to roll out the gadget might be to install it first as a gadget, enabled only in the "File" namespace. If people like it and no problems occurred, enable it later for everyone. Finally consider switching on inline display of notes.
#'''Where can I test this feature?'''
#:On your [[#Trying it out|personal image note sandbox page]].

== Problems? ==

Despite having been tested on a wide array of browsers, it is not impossible that this script has still errors or that it doesn't work as it should on some browsers. If you have any problems with this script, report them at [[MediaWiki talk:Gadget-ImageAnnotator.js]].

When reporting an error, always include the following information:
*Which browser are you using? What version?
*Which other gadgets have you enabled?
*Which skin are you using (Monobook, Modern, Vector, other...)?
*What's your user interface language setting?
*What exactly did you do?
*If the error occurred when you were trying to save a note: were there any error messages in the editor's window?
*Were there any error messages displayed at the top of the page?
*If you have a modern browser that does have an "error console" of some sort: were there any errors reported there?

For the last three points: we of course also need to know what these messages said exactly.

=== Emergency switch-off ===

If you encounter severe problems, you can switch off ''ImageAnnotator'' by logging in and then setting a checkbox ''disable the image annotations'' in [[Special:Preferences#preftab-8|Gadgets Preferences]]. If you do so, you won't be able to see any image notes anymore: the script will not be executed.

If you feel the need to do this, please also make sure that you do report your problem at [[MediaWiki talk:Gadget-ImageAnnotator.js]], so that we have a chance of fixing it. We cannot fix problems that we don't even know about!

== Monitoring edits ==

* [{{fullurl:Special:RecentChanges|limit=500&tagfilter=small+image+note}} Image note edits creating very small note rectangles]

Filter that was supposed to tag all image notes edits was disabled because it triggered too often, and the [[:mw:Extension:AbuseFilter|extension]] apparently isn't made for general edit tagging.

== See also ==
* {{tl|Annotated picture finder}} : a tag for category headers, helping users to find annotated pictures within the category.
* [[:d:User:Lucas Werkmeister/Wikidata Image Positions|Wikidata Image Positions]]

[[Category:Commons help|Gadget-ImageAnnotator]]