Positioning a non-geographical image with markers

The Image Layer can be used for any type of spatial analysis, not just geographical analysis. Your image could be a human body, a process diagram, a semiconductor schematic, a soccer field? anything of interest to you on which you can reliably plot data on.

There are a number of steps to follow when creating non-geographical spatial visualizations; the challenge is to create a same coordinate system between your data and the image you use to provide the spatial context. Let's take the example of a process diagram.

Defining the coordinate system

Here we want to plot markers showing failure/success status over the diagram image. We need to create a coordinate system that will enable plotting markers on the diagram image. This can be done using a presentation program (Microsoft PowerPoint or another application) or a graphics editor to position the markers and by reporting the position to a spreadsheet. For this guide we use PowerPoint.

1. Once you have your image, open PowerPoint and set up the page to have the same size as your image
   
   
    
2. Insert your image on the page
   
3. Add the markers position as shapes on top of the image
   
4. Report each position to a spreadsheet with eventually related information such as names or other info
   
5. Now we need to transform the vertical positions. In PowerPoint, a vertical position value is based on the distance from the top left as opposed to Spotfire where it is based on the distance from the bottom left. We have to flip all the vertical positions using: "Image height - Y value"
   
6. Once done, we can remove the original Y column and we are ready to use our diagram image and the positions reported in the spreadsheet.

Creating the visualization in Spotfire

Now that we have the image and the data ready, we can create the visualization in Spotfire as follows:

1. Open Spotfire, import your spreadsheet and create a Map Chart visualization
2. Right-click the Map Chart visualization, select Properties, go to the Layers section
3. Remove the Map Layer
   
    
4. Go to the Appearance section in the Properties
5. Set the Map Chart CRS to "None"
   
    
6. From the Layers section, open your data layer Settings (here "Status") and set CRS to "None" from the Data section
   
    
7. From the Layers section in the Properties, select Add > Image Layer and click "Browse..." to select you image
   
    
8. Set CRS to "None"
9. Go to "Extent Settings..." and make sure the extent is equal to the size of your image, Y low & X low starting as zero
   
    
10. You can now close the Properties, your visualization should be ready to use.
    

Now that your visualization is ready, you can always tweak the positions using the replace value feature to change a bit the positions to their desired locations if needed.