I have downloaded an image from google earth with four control points ready to geo reference. I enter the first two points and everything is fine. Then I enter a third point, the image disappears and the 'zoom to layer' just shows the control points with a blank map behind them.

Has anyone else experienced this and would know how to rectify it? I don't know if its a problem with the control points or the image itself.

  • Do you get a warning about your points being collinear, or not well distributed?
    – CSB
    Nov 1 '18 at 12:53
  • Yes I do, with a warning that the image may be warped. Is this part of the issue? Nov 3 '18 at 9:20

Try using Rotate, Shift, and Scale instead of control points. Controls points can get tricky if there are 3+ control points. Also, remember to click Update Georeferencing so your changes save.



The warning you're getting (as you confirmed in your comment above) means that you need to distribute your GCPs more evenly throughout the image. They should not be placed in only one area of the image, or in a pattern resembling a line. If possible, it's good to have at least one near each corner.

It's also possible that the issue is occurring because of the order you're adding them. Try adding them so that each new point is the furthest one from all the others. For example, if your GCPs are in the pattern of a 5 on a die

enter image description here

add at least three corners before adding the middle point. If you were to add two corners and the middle first (so that you could draw a line through them), you would likely have the issue you're encountering.

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