Images Reference

Document attributes and values
Attribute	Value(s)	Example Syntax	Comments
`imagesdir`	empty, filesystem path, or base URL	`:imagesdir: images`	Added in front of a relative image target, joined using a file separator if needed. Not used if the image target is an absolute URL or path. Default value is empty.

Block and inline image attributes and values
Attribute	Value(s)	Example Syntax	Comments
`id`	User defined text	`id=sunset-img` (or `[[sunset-img]]` or `[#sunset-img]` above block macro)
`alt`	User defined text in first position of attribute list or named attribute	`image::sunset.jpg[Brilliant sunset]` (or `alt=Sunset`)
`fallback`	Image path relative to `imagesdir` or an absolute path or URL	`image::tiger.svg[fallback=tiger.png]`	Only applicable if target is an SVG and opts=interactive
`title`	User defined text	in attrlist: `title="A mountain sunset"` (enclosing quotes only required if value contains a comma) above block macro: `.A mountain sunset`	Blocks: title displayed below image Inline: title displayed as tooltip
`format`	The format of the image, specified as a sub-MIME type (except in the case of an SVG, which is specified as `svg`).	`format=svg`	Only necessary when the converter needs to know the format of the image and the target does not end in a file extension (or otherwise cannot be detected).
`caption`	User defined text	`caption="Figure 8: "`	Only applies to block images.
`width`	User defined size in pixels	`image::sunset.jpg[Sunset,300]` (or `width=300`)
`height`	User defined size in pixels	`image::sunset.jpg[Sunset,300,200]` (or `height=200`)	The height should only be set if the width attribute is set and must respect the aspect ratio of the image.
`link`	User defined location of external URI	`link=https://www.flickr.com/photos/javh/5448336655`
`window`	User defined window target for the `link` attribute	`window=_blank`
`scale`	A scaling factor to apply to the intrinsic image dimensions	`scale=80`	DocBook only
`scaledwidth`	User defined width for block images	`scaledwidth=25%`	DocBook and Asciidoctor PDF only
`pdfwidth`	User defined width for images in a PDF	`pdfwidth=80vw`	Asciidoctor PDF only
`align`	`left`, `center`, `right`	`align=left`	Block images only. `align` and `float` attributes are mutually exclusive.
`float`	`left`, `right`	`float=right`	Block images only. `float` and `align` attributes are mutually exclusive. To scope the float, use a float group.
`role`	user-defined, `left`, `right`, `th`, `thumb`, `related`, `rel`	`role="thumb right"` (or `[.thumb.right]` above block macro)	The role is preferred to specify the float position for an image. Role shorthand (`.`) can only be used in block attribute list above a block image.
`opts`	Additional options for link creation and SVG targets.	`image::sunset.jpg[Sunset, link=https://example.org, opts=nofollow]` `image::chart.svg[opts=inline]`	Option names include: `nofollow`, `noopener`, `inline` (SVG only), `interactive` (SVG only)