Image

Overview

The image trace type is used to display raster images in a plot. This is particularly useful for visualizing images as data or overlaying images on other plot types. The image trace allows for the rendering of pixel data in a 2D grid.

You can customize the image size, position, and color scaling to represent image data effectively. Images can be used in scientific visualizations, geographic data, or any scenario where image data is needed.

Common Uses

• Raster Images: Displaying raster images in data visualizations.
• Geographic Maps: Visualizing maps or satellite images.
• Image Data: Rendering images directly as part of data exploration and analysis.

Check out the Attributes for the full set of configuration options

Examples

Common Configurations

Simple Image PlotImage Plot with Custom ColorscaleImage Plot with Axis Annotations

Here's a simple image plot displaying an image based on pixel values:

You can copy this code below to create this chart in your project:

models:
  - name: image-data
    args:
      - echo
      - |
        z
        0,0,1,1
        1,0,0,1
        1,1,0,0
traces:
  - name: Simple Image Plot
    model: ref(image-data)
    props:
      type: image
      z: query(z)
charts:
  - name: Simple Image Chart
    traces:
      - ref(Simple Image Plot)
    layout:
      title:
        text: Simple Image Plot<br><sub>Raster Image Display</sub>

This example demonstrates an image plot with a custom colorscale to better represent the image data:

Here's the code:

models:
  - name: image-data-custom
    args:
      - echo
      - |
        z
        0.1,0.2,0.3,0.4
        0.5,0.6,0.7,0.8
        0.9,1.0,0.2,0.3
traces:
  - name: Image Plot with Custom Colorscale
    model: ref(image-data-custom)
    props:
      type: image
      z: query(z)
      colorscale: "Viridis"
charts:
  - name: Image Plot with Custom Colorscale
    traces:
      - ref(Image Plot with Custom Colorscale)
    layout:
      title:
        text: Image Plot with Custom Colorscale<br><sub>Custom Coloring for Image Data</sub>

This example shows an image plot with axis labels and annotations to provide context for the image data:

Here's the code:

models:
  - name: image-data-annotated
    args:
      - echo
      - |
        z
        1,0,0,1
        0,1,1,0
        0,0,1,1
traces:
  - name: Image Plot with Axis Annotations
    model: ref(image-data-annotated)
    props:
      type: image
      z: query(z)
charts:
  - name: Image Plot with Axis Annotations
    traces:
      - ref(Image Plot with Axis Annotations)
    layout:
      title:
        text: Image Plot with Axis Annotations<br><sub>Image with Axes</sub>
      xaxis:
        title:
          text: "X Axis"
      yaxis:
        title:
          text: "Y Axis"

Attributes

These attributes apply to traces where trace.props.type is set to image. You would configure these attributes on the trace with the trace.props object.

colormodel: 'enumerated , one of ( "rgb" | "rgba" | "rgba256" | "hsl" | "hsla" )' #(1)!
customdata: 'data array' #(2)!
dx: 'number' #(3)!
dy: 'number' #(4)!
hoverinfo: 'flaglist string. any combination of "x", "y", "z", "color", "name", "text"
  joined with a "+" or "all" or "none" or "skip".' #(5)!
hoverlabel:
  align: 'enumerated or array of enumerateds , one of ( "left" | "right" | "auto"
    )' #(6)!
  bgcolor: 'color or array of colors' #(7)!
  bordercolor: 'color or array of colors' #(8)!
  font:
    color: color or array of colors
    family: 'string or array of strings' #(9)!
    size: number or array of numbers greater than or equal to 1
  namelength: 'integer or array of integers greater than or equal to -1' #(10)!
hovertemplate: 'string or array of strings' #(11)!
hovertext: 'data array' #(12)!
ids: 'data array' #(13)!
legendgrouptitle:
  font:
    color: color
    family: 'string' #(14)!
    size: number greater than or equal to 1
  text: 'string' #(15)!
legendrank: 'number' #(16)!
legendwidth: 'number greater than or equal to 0' #(17)!
meta: 'number or categorical coordinate string' #(18)!
opacity: 'number between or equal to 0 and 1' #(19)!
source: 'string' #(20)!
text: 'data array' #(21)!
type: image
uirevision: 'number or categorical coordinate string' #(22)!
visible: 'enumerated , one of ( true | false | "legendonly" )' #(23)!
x0: 'number or categorical coordinate string' #(24)!
xaxis: 'subplotid' #(25)!
y0: 'number or categorical coordinate string' #(26)!
yaxis: 'subplotid' #(27)!
z: 'data array' #(28)!
zmax: 'array' #(29)!
zmin: 'array' #(30)!
zsmooth: 'enumerated , one of ( "fast" | false )' #(31)!

1. 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.
2. 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
3. Set the pixel's horizontal size.
4. Set the pixel's vertical size
5. 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.
6. 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
7. Sets the background color of the hover labels for this trace
8. Sets the border color of the hover labels for this trace.
9. 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".
10. 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.
11. 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. variables z, color and colormodel. Anything contained in tag <extra> is displayed in the secondary box, for example "{fullData.name}". To hide the secondary box completely, use an empty tag <extra></extra>.
12. Same as text.
13. 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.
14. 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".
15. Sets the title of the legend group.
16. 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.
17. Sets the width (in px or fraction) of the legend for this trace.
18. 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.
19. Sets the opacity of the trace.
20. Specifies the data URI of the image to be visualized. The URI consists of "data:image/[][;base64],"
21. Sets the text elements associated with each z value.
22. 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.
23. 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).
24. Set the image's x position.
25. 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.
26. Set the image's y position.
27. 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.
28. A 2-dimensional array in which each element is an array of 3 or 4 numbers representing a color.
29. 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].
30. 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].
31. Picks a smoothing algorithm used to smooth z data. This only applies for image traces that use the source attribute.