MATLAB Figure Reference: image Traces

A image trace is a struct inside fig.data which has type equal to 'image'. This section lists all of the valid keys that a image struct can contain.

Display an image, i.e. data on a 2D regular raster. By default, when an image is displayed in a subplot, its y axis will be reversed (ie. `autorange: 'reversed'`), constrained to the domain (ie. `constrain: 'domain'`) and it will have the same scale as its x axis (ie. `scaleanchor: 'x,`) in order for pixels to be rendered as squares.

  • type
    Parent: data[type=image]
    Type: 'image'
  • name
    Parent: data[type=image]
    Type: string

    Sets the trace name. The trace name appears as the legend item and on hover.

  • visible
    Parent: data[type=image]
    Type: enumerated , one of ( true | false | 'legendonly' )
    Default: true

    Determines whether or not this trace is visible. If 'legendonly', the trace is not drawn, but can appear as a legend item (provided that the legend itself is visible).

  • legend
    Parent: data[type=image]
    Type: subplotid
    Default: legend

    Sets the reference to a legend to show this trace in. References to these legends are 'legend', 'legend2', 'legend3', etc. Settings for these legends are set in the layout, under `layout.legend`, `layout.legend2`, etc.

  • legendrank
    Parent: data[type=image]
    Type: number
    Default: 1000

    Sets the legend rank for this trace. Items and groups with smaller ranks are presented on top/left side while with 'reversed' `legend.traceorder` they are on bottom/right side. The default legendrank is 1000, so that you can use ranks less than 1000 to place certain items before all unranked items, and ranks greater than 1000 to go after all unranked items. When having unranked or equal rank items shapes would be displayed after traces i.e. according to their order in data and layout.

  • legendgrouptitle
    Parent: data[type=image]
    Type: struct containing one or more of the keys listed below.
    • font
      Parent: data[type=image].legendgrouptitle
      Type: struct containing one or more of the keys listed below.

      Sets this legend group's title font.

      • color
        Parent: data[type=image].legendgrouptitle.font
        Type: color
      • family
        Parent: data[type=image].legendgrouptitle.font
        Type: string

        HTML font family - the typeface that will be applied by the web browser. The web browser will only be able to apply a font if it is available on the system which it operates. Provide multiple font families, separated by commas, to indicate the preference in which to apply fonts if they aren't available on the system. The Chart Studio Cloud (at https://chart-studio.plotly.com or on-premise) generates images on a server, where only a select number of fonts are installed and supported. These include 'Arial', 'Balto', 'Courier New', 'Droid Sans', 'Droid Serif', 'Droid Sans Mono', 'Gravitas One', 'Old Standard TT', 'Open Sans', 'Overpass', 'PT Sans Narrow', 'Raleway', 'Times New Roman'.

      • lineposition
        Parent: data[type=image].legendgrouptitle.font
        Type: flaglist string. Any combination of 'under', 'over', 'through' joined with a '+' OR 'none'.
        Examples: 'under', 'over', 'under+over', 'under+over+through', 'none'
        Default: 'none'

        Sets the kind of decoration line(s) with text, such as an 'under', 'over' or 'through' as well as combinations e.g. 'under+over', etc.

      • shadow
        Parent: data[type=image].legendgrouptitle.font
        Type: string
        Default: 'none'

        Sets the shape and color of the shadow behind text. 'auto' places minimal shadow and applies contrast text font color. See https://developer.mozilla.org/en-US/docs/Web/CSS/text-shadow for additional options.

      • size
        Parent: data[type=image].legendgrouptitle.font
        Type: number greater than or equal to 1
      • style
        Parent: data[type=image].legendgrouptitle.font
        Type: enumerated , one of ( 'normal' | 'italic' )
        Default: 'normal'

        Sets whether a font should be styled with a normal or italic face from its family.

      • textcase
        Parent: data[type=image].legendgrouptitle.font
        Type: enumerated , one of ( 'normal' | 'word caps' | 'upper' | 'lower' )
        Default: 'normal'

        Sets capitalization of text. It can be used to make text appear in all-uppercase or all-lowercase, or with each word capitalized.

      • variant
        Parent: data[type=image].legendgrouptitle.font
        Type: enumerated , one of ( 'normal' | 'small-caps' | 'all-small-caps' | 'all-petite-caps' | 'petite-caps' | 'unicase' )
        Default: 'normal'

        Sets the variant of the font.

      • weight
        Parent: data[type=image].legendgrouptitle.font
        Type: integer between or equal to 1 and 1000
        Default: normal

        Sets the weight (or boldness) of the font.

    • text
      Parent: data[type=image].legendgrouptitle
      Type: string
      Default: ''

      Sets the title of the legend group.

  • legendwidth
    Parent: data[type=image]
    Type: number greater than or equal to 0

    Sets the width (in px or fraction) of the legend for this trace.

  • opacity
    Parent: data[type=image]
    Type: number between or equal to 0 and 1
    Default: 1

    Sets the opacity of the trace.

  • ids
    Parent: data[type=image]
    Type: array

    Assigns id labels to each datum. These ids for object constancy of data points during animation. Should be an array of strings, not numbers or any other type.

  • zorder
    Parent: data[type=image]
    Type: integer
    Default: 0

    Sets the layer on which this trace is displayed, relative to other SVG traces on the same subplot. SVG traces with higher `zorder` appear in front of those with lower `zorder`.

  • x0
    Parent: data[type=image]
    Type: number or categorical coordinate string
    Default: 0

    Set the image's x position. The left edge of the image (or the right edge if the x axis is reversed or dx is negative) will be found at xmin=x0-dx/2

  • dx
    Parent: data[type=image]
    Type: number
    Default: 1

    Set the pixel's horizontal size.

  • y0
    Parent: data[type=image]
    Type: number or categorical coordinate string
    Default: 0

    Set the image's y position. The top edge of the image (or the bottom edge if the y axis is NOT reversed or if dy is negative) will be found at ymin=y0-dy/2. By default when an image trace is included, the y axis will be reversed so that the image is right-side-up, but you can disable this by setting yaxis.autorange=true or by providing an explicit y axis range.

  • dy
    Parent: data[type=image]
    Type: number
    Default: 1

    Set the pixel's vertical size

  • z
    Parent: data[type=image]
    Type: array

    A 2-dimensional array in which each element is an array of 3 or 4 numbers representing a color.

  • source
    Parent: data[type=image]
    Type: string

    Specifies the data URI of the image to be visualized. The URI consists of "data:image/[<media subtype>][;base64],<data>"

  • text
    Parent: data[type=image]
    Type: array

    Sets the text elements associated with each z value.

  • hovertext
    Parent: data[type=image]
    Type: array

    Same as `text`.

  • hoverinfo
    Parent: data[type=image]
    Type: flaglist string. Any combination of 'x', 'y', 'z', 'color', 'name', 'text' joined with a '+' OR 'all' or 'none' or 'skip'.
    Examples: 'x', 'y', 'x+y', 'x+y+z', 'all'
    Default: 'x+y+z+text+name'

    Determines which trace information appear on hover. If `none` or `skip` are set, no information is displayed upon hovering. But, if `none` is set, click and hover events are still fired.

  • hovertemplate
    Parent: data[type=image]
    Type: string or array of strings
    Default: ''

    Template string used for rendering the information that appear on hover box. Note that this will override `hoverinfo`. Variables are inserted using %{variable}, for example "y: %{y}" as well as %{xother}, {%_xother}, {%_xother_}, {%xother_}. When showing info for several points, 'xother' will be added to those with different x positions from the first point. An underscore before or after '(x|y)other' will add a space on that side, only when this field is shown. Numbers are formatted using d3-format's syntax %{variable:d3-format}, for example "Price: %{y:$.2f}". https://github.com/d3/d3-format/tree/v1.4.5#d3-format for details on the formatting syntax. Dates are formatted using d3-time-format's syntax %{variable|d3-time-format}, for example "Day: %{2019-01-01|%A}". https://github.com/d3/d3-time-format/tree/v2.2.3#locale_format for details on the date formatting syntax. The variables available in `hovertemplate` are the ones emitted as event data described at this link https://plotly.com/javascript/plotlyjs-events/#event-data. Additionally, every attributes that can be specified per-point (the ones that are `arrayOk: true`) are available. Finally, the template string has access to variables `z`, `color` and `colormodel`. Anything contained in tag `<extra>` is displayed in the secondary box, for example "<extra>{fullData.name}</extra>". To hide the secondary box completely, use an empty tag `<extra></extra>`.

  • meta
    Parent: data[type=image]
    Type: number or categorical coordinate string

    Assigns extra meta information associated with this trace that can be used in various text attributes. Attributes such as trace `name`, graph, axis and colorbar `title.text`, annotation `text` `rangeselector`, `updatemenues` and `sliders` `label` text all support `meta`. To access the trace `meta` values in an attribute in the same trace, simply use `%{meta[i]}` where `i` is the index or key of the `meta` item in question. To access trace `meta` in layout attributes, use `%{data[n[.meta[i]}` where `i` is the index or key of the `meta` and `n` is the trace index.

  • customdata
    Parent: data[type=image]
    Type: array

    Assigns extra data each datum. This may be useful when listening to hover, click and selection events. Note that, 'scatter' traces also appends customdata items in the markers DOM elements

  • xaxis
    Parent: data[type=image]
    Type: subplotid
    Default: x

    Sets a reference between this trace's x coordinates and a 2D cartesian x axis. If 'x' (the default value), the x coordinates refer to `layout.xaxis`. If 'x2', the x coordinates refer to `layout.xaxis2`, and so on.

  • yaxis
    Parent: data[type=image]
    Type: subplotid
    Default: y

    Sets a reference between this trace's y coordinates and a 2D cartesian y axis. If 'y' (the default value), the y coordinates refer to `layout.yaxis`. If 'y2', the y coordinates refer to `layout.yaxis2`, and so on.

  • colormodel
    Parent: data[type=image]
    Type: enumerated , one of ( 'rgb' | 'rgba' | 'rgba256' | 'hsl' | 'hsla' )

    Color model used to map the numerical color components described in `z` into colors. If `source` is specified, this attribute will be set to `rgba256` otherwise it defaults to `rgb`.

  • zmax
    Parent: data[type=image]
    Type: cell array

    Array defining the higher bound for each color component. Note that the default value will depend on the colormodel. For the `rgb` colormodel, it is [255, 255, 255]. For the `rgba` colormodel, it is [255, 255, 255, 1]. For the `rgba256` colormodel, it is [255, 255, 255, 255]. For the `hsl` colormodel, it is [360, 100, 100]. For the `hsla` colormodel, it is [360, 100, 100, 1].

  • zmin
    Parent: data[type=image]
    Type: cell array

    Array defining the lower bound for each color component. Note that the default value will depend on the colormodel. For the `rgb` colormodel, it is [0, 0, 0]. For the `rgba` colormodel, it is [0, 0, 0, 0]. For the `rgba256` colormodel, it is [0, 0, 0, 0]. For the `hsl` colormodel, it is [0, 0, 0]. For the `hsla` colormodel, it is [0, 0, 0, 0].

  • zsmooth
    Parent: data[type=image]
    Type: enumerated , one of ( 'fast' | false )

    Picks a smoothing algorithm used to smooth `z` data. This only applies for image traces that use the `source` attribute.

  • hoverlabel
    Parent: data[type=image]
    Type: struct containing one or more of the keys listed below.
    • align
      Parent: data[type=image].hoverlabel
      Type: enumerated or array of enumerateds , one of ( 'left' | 'right' | 'auto' )
      Default: 'auto'

      Sets the horizontal alignment of the text content within hover label box. Has an effect only if the hover label text spans more two or more lines

    • bgcolor
      Parent: data[type=image].hoverlabel
      Type: color or array of colors

      Sets the background color of the hover labels for this trace

    • bordercolor
      Parent: data[type=image].hoverlabel
      Type: color or array of colors

      Sets the border color of the hover labels for this trace.

    • font
      Parent: data[type=image].hoverlabel
      Type: struct containing one or more of the keys listed below.

      Sets the font used in hover labels.

      • color
        Parent: data[type=image].hoverlabel.font
        Type: color or array of colors
      • family
        Parent: data[type=image].hoverlabel.font
        Type: string or array of strings

        HTML font family - the typeface that will be applied by the web browser. The web browser will only be able to apply a font if it is available on the system which it operates. Provide multiple font families, separated by commas, to indicate the preference in which to apply fonts if they aren't available on the system. The Chart Studio Cloud (at https://chart-studio.plotly.com or on-premise) generates images on a server, where only a select number of fonts are installed and supported. These include 'Arial', 'Balto', 'Courier New', 'Droid Sans', 'Droid Serif', 'Droid Sans Mono', 'Gravitas One', 'Old Standard TT', 'Open Sans', 'Overpass', 'PT Sans Narrow', 'Raleway', 'Times New Roman'.

      • lineposition
        Parent: data[type=image].hoverlabel.font
        Type: flaglist string. Any combination of 'under', 'over', 'through' joined with a '+' OR 'none'.
        Examples: 'under', 'over', 'under+over', 'under+over+through', 'none'
        Default: 'none'

        Sets the kind of decoration line(s) with text, such as an 'under', 'over' or 'through' as well as combinations e.g. 'under+over', etc.

      • shadow
        Parent: data[type=image].hoverlabel.font
        Type: string or array of strings
        Default: 'none'

        Sets the shape and color of the shadow behind text. 'auto' places minimal shadow and applies contrast text font color. See https://developer.mozilla.org/en-US/docs/Web/CSS/text-shadow for additional options.

      • size
        Parent: data[type=image].hoverlabel.font
        Type: number or array of numbers greater than or equal to 1
      • style
        Parent: data[type=image].hoverlabel.font
        Type: enumerated or array of enumerateds , one of ( 'normal' | 'italic' )
        Default: 'normal'

        Sets whether a font should be styled with a normal or italic face from its family.

      • textcase
        Parent: data[type=image].hoverlabel.font
        Type: enumerated or array of enumerateds , one of ( 'normal' | 'word caps' | 'upper' | 'lower' )
        Default: 'normal'

        Sets capitalization of text. It can be used to make text appear in all-uppercase or all-lowercase, or with each word capitalized.

      • variant
        Parent: data[type=image].hoverlabel.font
        Type: enumerated or array of enumerateds , one of ( 'normal' | 'small-caps' | 'all-small-caps' | 'all-petite-caps' | 'petite-caps' | 'unicase' )
        Default: 'normal'

        Sets the variant of the font.

      • weight
        Parent: data[type=image].hoverlabel.font
        Type: integer or array of integers between or equal to 1 and 1000
        Default: normal

        Sets the weight (or boldness) of the font.

    • namelength
      Parent: data[type=image].hoverlabel
      Type: integer or array of integers greater than or equal to -1
      Default: 15

      Sets the default length (in number of characters) of the trace name in the hover labels for all traces. -1 shows the whole name regardless of length. 0-3 shows the first 0-3 characters, and an integer >3 will show the whole name if it is less than that many characters, but if it is longer, will truncate to `namelength - 3` characters and add an ellipsis.

  • uirevision
    Parent: data[type=image]
    Type: number or categorical coordinate string

    Controls persistence of some user-driven changes to the trace: `constraintrange` in `parcoords` traces, as well as some `editable: true` modifications such as `name` and `colorbar.title`. Defaults to `layout.uirevision`. Note that other user-driven trace attribute changes are controlled by `layout` attributes: `trace.visible` is controlled by `layout.legend.uirevision`, `selectedpoints` is controlled by `layout.selectionrevision`, and `colorbar.(x|y)` (accessible with `config: {editable: true}`) is controlled by `layout.editrevision`. Trace changes are tracked by `uid`, which only falls back on trace index if no `uid` is provided. So if your app can add/remove traces before the end of the `data` array, such that the same trace has a different index, you can still preserve user-driven changes if you give each trace a `uid` that stays with it as it moves.