How to draw lines on the geotiff orthomosaic image

Analysis - Discussion and Q&A
1

Hi everyone.

I hope you are all fine.
I had a requirement where I need to draw some boundaries on the Orthosomasic image in Qgis. I tried doing it by creating a print layout but there was a lot of pixel loss I don’t know why.

I want to know is there a way to draw on top of the ortho like creating a polygon. The customer wants so that he can mark his boundaries and then I can deliver the ortho to him. Thanks in advance.

How can we do this with any software like Qgis or arcgis etc.

2

If I understand correctly something similar literally just came up in a question from a friend of mine so I made this quick snippet. You can draw a polyline as well, but if you want each segment dimensioned they need to be individual lines. For a polygon just make the correct content choice when setting up the shapefile layer.

QGIS Draw Dimensioned Lines

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which Shapefile have you used there?

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Thanks for that Info. I would also want to know How can I divide my Orthomosiac into parts and get it exported.

Like once I add lines the client wants to cut the image into few parts and want it to be delivered as different parts. How do I do that?

1 Like
5

There is only one SHP file with different vector entities that can be applied. This method can be used like CAD where each SHP is in the project as a layer which can be colored specifically and turn on/off. The available selections in QGIS are points, multipoints, lines (polylines) and polygons. All entities can be labeled with the same workflow I showed. There is so much more, but just a 10% knowledge should cover 90% of what a surveyor or mapper should need to use.

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You get the option of what extents you want to use when saving/exporting. You can save as georeferenced or simple non-georeferenced maps/images.

Projects>Import/export>Image/PDF/DXF (non-georeferenced)

Layers
Right-click>Export>Save As (georeferenced)

Int eh case of the project in the example it is a 10-mile roadway that I have as separate 1-mile section and hence 10 separate orthos. I bring them into a single QGIS project and work with them there. It is the only program I have that will handle that much data.