HighlightImage

HighlightImage[image,roi]

highlights the specified region of interest roi in image.

HighlightImage[image,{roi₁,roi₂,…}]

highlights several regions of interest roi_i.

HighlightImage[image,{…,w[roi_i],…}]

highlights using a feature defined by the symbolic wrapper w.

HighlightImage[image,fg,bgstyle]

applies the styling bgstyle to the complement of all the regions of interest.

Details and Options

HighlightImage is used for highlighting particular regions or features in an image. It returns the highlighted image as a Graphics object.
The region of interest roi can be any of the following:

	{{x₁,y₁},…}	a list of image positions
	region	a 2D geometric region (Point, Line, Disk, etc.)
	labelmatrix	a 2D label matrix specifying image components
	maskimage	nonzero pixels of an Image object
	graphics	a Graphics object
	f	a region returned by a function f
	<\|label₁->roi₁, …\|>	an association of labeled regions

Labels in labeled associations <|label₁->roi₁, …|> are used for labeling and legending.
By default, using DataRange->Full, positions {x_i,y_i} and geometric regions are assumed to be in the standard image coordinate system.
The following wrappers w can be used:

	Annotation[roi,label]	provide an annotation
	Button[roi,action]	define an action to execute when the element is clicked
	EventHandler[roi,…]	define a general event handler for the element
	Hyperlink[roi,uri]	make the element act as a hyperlink
	ImageMarker[roi,…]	place a marker at the medoid of roi
	Labeled[roi_i,…]	place a marker at the medoid of roi
	Legended[roi,lbl]	include the label lbl in the legend
	PopupWindow[roi,cont]	attach a popup window to the element
	StatusArea[roi,label]	display in the status area when the element is moused over
	Style[roi,opts]	show the element using the specified styles
	Tooltip[roi,label]	attach an arbitrary tooltip to the element

Use HighlightImage[image,{…,style,roi,…}] to specify a style for the region roi.
Basic style specifications include:

	Automatic	automatically select the highlighting method
	color	color specification (RGBColor, LABColor, etc.)
	directive	any valid graphics directive (PointSize, Thickness, etc.)

By default, the most suitable highlighting style is used.
Additional style specifications include:
"Blur",{"Blur",r} blur using range r neighborhoods

"Boundary",{"Boundary",t} highlight the boundary using thickness t
Nested lists of regions of interest and styles can be given. Style specifications remain in effect only until the end of the list that contains them.
The background is taken to be the complement of all regions of interest. The following bgstyle specifications can be used:

		"Blur", {"Blur",r}	blur using range r neighborhoods
		"Darken",{"Darken",a}	blend with black (default )
		"Lighten",{"Lighten",a}	blend with white (default )
		"Desaturate",{"Desaturate",s}	desaturate
		"Remove"	make background transparent
		{"Remove",color}	replace background with color
		f	perform f on the background

With an explicit bgstyle, the foreground opacity is set to 0. Use Opacity[α] to specify a different foreground opacity.
HighlightImage accepts all Graphics options with the following changes and additions: [List of all options]

DataRange	Full	range of coordinates in the original image
ImageLabels	Automatic	how to label regions of interest
ImageLegends	None	how to add a legend
PlotRange	Automatic	range of coordinates to include
PlotRangePadding	None	how much to pad the range of values

Possible settings for ImageLabels and ImageLegends include:

	{lbl₁,lbl₂,…}	use an explicit lbl_i for roi_i
	Automatic	automatic labeling and legending
	None	no label or legend
	"Expressions"	use the arbitrary functions f

Typical settings for DataRange include:
Automatic {{0,1},{0,h/w}}

Full {{0,w},{0,h}}

{{left,right},{bottom,top}} explicit coordinate ranges in 2D
Typical settings for PlotRange include:
All all points are included

Automatic same as DataRange settings

{{left,right},{bottom,top}} explicit coordinate ranges

List of all options

AlignmentPoint	Center	the default point in the graphic to align with
AspectRatio	Automatic	ratio of height to width
Axes	False	whether to draw axes
AxesLabel	None	axes labels
AxesOrigin	Automatic	where axes should cross
AxesStyle	{}	style specifications for the axes
Background	None	background color for the plot
BaselinePosition	Automatic	how to align with a surrounding text baseline
BaseStyle	{}	base style specifications for the graphic
ContentSelectable	Automatic	whether to allow contents to be selected
CoordinatesToolOptions	Automatic	detailed behavior of the coordinates tool
DataRange	Full	range of coordinates in the original image
Epilog	{}	primitives rendered after the main plot
FormatType	TraditionalForm	the default format type for text
Frame	False	whether to put a frame around the plot
FrameLabel	None	frame labels
FrameStyle	{}	style specifications for the frame
FrameTicks	Automatic	frame ticks
FrameTicksStyle	{}	style specifications for frame ticks
GridLines	None	grid lines to draw
GridLinesStyle	{}	style specifications for grid lines
ImageLabels	Automatic	how to label regions of interest
ImageLegends	None	how to add a legend
ImageMargins	0.	the margins to leave around the graphic
ImagePadding	All	what extra padding to allow for labels etc.
ImageSize	Automatic	the absolute size at which to render the graphic
LabelStyle	{}	style specifications for labels
Method	Automatic	details of graphics methods to use
PlotLabel	None	an overall label for the plot
PlotRange	Automatic	range of coordinates to include
PlotRangeClipping	False	whether to clip at the plot range
PlotRangePadding	None	how much to pad the range of values
PlotRegion	Automatic	the final display region to be filled
PreserveImageOptions	Automatic	whether to preserve image options when displaying new versions of the same graphic
Prolog	{}	primitives rendered before the main plot
RotateLabel	True	whether to rotate y labels on the frame
Ticks	Automatic	axes ticks
TicksStyle	{}	style specifications for axes ticks

Examples

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Basic Examples (3)

Highlight the corners of an image:

Highlight a region of interest by dehighlighting the rest of the image:

Highlight a region of interest:

Scope (23)

Regions (8)

Point Regions (1)

Highlight a list of points:

Use a list of positions:

Use an explicit Point wrapper:

Use an ImageMarker wrapper:

Specify a marker:

Curve Regions (1)

Highlight a one-dimensional region:

Area Regions (3)

Use an Image object as the region:

Use a Graphics primitive to describe what to highlight:

Use a Graphics object as the region:

Use a geometric region to describe what to highlight:

The region of interest can be a Graphics object generated by any function:

Whenever the region is given as an image, it is assumed to be a 2D region:

Highlight only the detected pixels by removing the boundary:

Compare the result with the exact pixel-wise color replacement:

Label Matrices (2)

Highlight connected components of a binary image:

Highlight segments of an image after performing watershed transform:

Highlight all components:

Delete border components and highlight the rest:

Other Graphics Elements (1)

Use an Inset:

Use a Text element:

Styling (15)

Region Styling (3)

Specify a highlighting color:

Highlight the region using a solid color:

Highlight the boundary of a region:

Use Graphics directives to customize the region:

Background Styling (6)

Highlight the image by decreasing the background brightness:

Highlight the image by increasing the background brightness:

Highlight the region of interest by converting the background to gray scale:

Use a specific saturation value:

Blur the background to highlight the foreground:

Use a custom function to highlight the background:

Remove the background:

Replace the removed background with a specific color:

Labeling & Legending (5)

Label image faces:

Detect faces and label them with estimated age:

Specify labels for each dataset of points:

Create a legend using the provided labels:

Highlight and label two image segments:

Wrappers (1)

Add tooltips on points of interest:

Compute position and strength of keypoints:

Options (7)

DataRange (1)

The default data range is determined by the dimensions of the image:

This is equivalent to DataRange->Full:

Use DataRange->Automatic for a normalized range on the axis:

Use a custom range:

GridLines (1)

By default, no grid lines are shown:

Show grid lines:

Specify grid lines to show:

ImageLabels (2)

By default, no label is used for the highlighted regions:

Use ImageLabels{"lbl₁","lbl2",…} to define labels for each region:

Association keys are automatically used as labels:

Use ImageLabelsNone to disable automatic labeling:

ImageLegends (2)

Use ImageLegends{"lbl₁","lbl2",…} to define labels for each region:

Legends are matched by scanning the list of regions depth first:

Association keys automatically used as labels:

Use ImageLegendsAutomatic to enable automatic legending:

Use ImageLabelsNone to also disable labeling:

PlotRange (1)

The default plot range is determined by the dimensions of the image:

Use PlotRange->All to see all regions:

Use a custom range:

Applications (5)

Blur faces in an image:

Perform and visualize a semantic segmentation of an image using a neural network:

Define an evaluator function that can work on any image dimension:

Segment an image:

Highlight labeled segments:

Highlight segments and use legends to show labels:

Highlight strong and weak corners in different styles:

Segment an image and highlight the centers of the disk shapes with a marker:

Highlight multiple regions of interest:

Interactive Examples (1)

Apply an interactive spotlight to a scene:

Top

		"Blur",{"Blur",r}	blur using range r neighborhoods
		"Boundary",{"Boundary",t}	highlight the boundary using thickness t

	Automatic	{{0,1},{0,h/w}}
	Full	{{0,w},{0,h}}
	{{left,right},{bottom,top}}	explicit coordinate ranges in 2D

	All	all points are included
	Automatic	same as DataRange settings
	{{left,right},{bottom,top}}	explicit coordinate ranges