How to extract 1 band image (Boundaries) in Google Earth Engine Code Editor

Question

I am quite new in remote sensing and trying to get boundaries of fields to build a prediction model in R. I tried Canny and Hough algorithms but the results are not satisfying. Lastly, I tried the model in 'Segmentation Session EEUS18' by Noel Gorelick. Here is my problem:

• Gorelick's code: code.earthengine.google.com/?accept_repo=users/gorelick/examples
• Example images are in https://drive.google.com/open?id=1bFVgedyVfzwXCyp6ZVXkCp_KkRl3Uq66 -

Suppose that I got perimeter pixels after the snic algorithm as [PerimeterZoomOut]. I want to extract the lines as vectors in a shapefile.

I tried reduceToVector but it needs at least 2 bands whereas perimeter image has only 1 band.

I also want to add a constraint so that it would not extract unnecessary lines as [PerimeterZoomIn].

The difference is also as between [NDVIZoomIn] and [NDVIZoomOut]. I don't want the noise in the fields.

Are there any way of extraction NDVI and perimeter lines images as vectors? They both have only 1 band.

Answer 1

Here is my solution to the problem:

I first extract the image as raster with the following code:

//grouped lines

Export.image.toDrive({
  image: perimeterPixels,
  description: "Perimeters_scale20",
  folder: "Perimeters",
  region: geometry,
  scale: 20,
  maxPixels: 50000000000

});

//or more precise lines

Export.image.toDrive({
  image: perimeterPixels,
  description: "Perimeters_scale20",
  folder: "Perimeters",
  region: geometry,
  scale: 5,
  maxPixels: 50000000000

});

You need to adjust your 'image', 'description', 'region', and most importantly 'scale' as to your preference.

As you increase the scale, you get a raster more like ZoomOut image. Then you can convert it to a vector image with programs like QGIS. If you know to extract vector image directly from GEE Code Editor, please illuminate me!