Image Analysis using "Sample Point" Software

Image Analysis of Percent Coverage using "Sample Point" Software

Our group analyzed percent coverage of vegetation for all quadrats within the 17 transects using free software called "sample point". Sample point software can be downloaded through the following website: http://samplepoint.org/index.html. Once the program is downloaded, go to "Options" and select "Database Wizard - Create DB" so that you can create a database name with the images you are wanting to analyze. Create a database name (example: Transect_1). Select "Create/Populate Database" chose the images and then select "Done". You can select more than one image for each database created. For instance, I selected all of the images that were located in one transect so that each image for all 5 quadrats within a transect were analyzed and stored in one excel spreadsheet. Go to "Options" and click on "Select Database". Chose the database you just created. If this is your first time using sample point, you will need to create buttons of the species you are going to be analyzing. Go to "Options" and highlight "Create Buttons" then select "Create Custom Button Files". It is best to abbreviate each of the species' name you are creating a button for because long names tend to get cut off. Save the custom button files once you have entered all of the species' names you will be analyzing. After you have created a database and created a custom button, you need to upload the button file to your database. Go to "Options" and highlight "Create Buttons" then select "Load Custom Button File". Chose the button file that you need. This has to be complete each time you create a new database. You can always create or edit your custom button's file if needed. Now you need to chose the grid size (points to be analyzed for each image). Go to "Options" and highlight "Select Grid Size" then chose the number of sample points. In our research project were used 64 points. Now you are ready to begin analyzing your data using sample point. Click on "Begin" to get started. You will need to zoom into the image until you see a red cross-hair cursor. Enter a zoom value from 1 to 12 and click "Refresh". Click on the species' button that the middle of the Red Cross-hair is positioned on. You can always click "Back" if you chose the incorrect species. Once you have selected species names for all of the grid points and you have exhausted all of the images, go to "Options" and select "Create Statistics Files". Using 64 sample points to analyze marsh vegetation, I was able to complete all 5 images for one transect in approximately 25 - 30 minutes. I believe that the percent coverage accuracy should increase with an increase in the number of sample points being used to analyze the images.