I need to set the tiling for an orthophoto made. I want to conduct object based image analysis on the mosaics made in eCognition software. I am hoping to classify broad tropical marine habitat types, e.g. coral, sand, seagrass etc. Can anyone recommend how to go about deciding on the best grid resolution?
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Obviously the higher resolution the better the detection is going to be, but from my experience the native or even the 2in/px image can be too big for some programs. I typically download the 4in/px and it works well across all other integrations in our workflow.
Thanks for the reply Michael! So I know the resolution of my images - ranges from 5 - 8 cm/pixel depending on altitude. But for the mosaic I have to decide on the grid resolution - so would having 1m grid resolution be too large for most programs to compute, in your experience? If my orthophoto area works out about 800 m x 800 m this is gonna be a very large tiling level
Gotcha, seeing that you are in metric then that range should be fine even at the upper end. Are you not able to load the full ortho? You can download the ortho tiled straight from DroneDeploy.
Because I have such a large data set (2000 - 3000 images at the most), I think it has been advised to split the orthophoto into tiles so that it has a greater resolution for when conducting object-based image analysis - classifying tropical marine habitat types of coral, sand, rubble, seagrass etc. Because of this I dont want to limit my ability to make classifications because of a bad resolution but also I want to make sure that there are not too many tiles to impede OBIA in eCognition.
I agree. With that many images then tiling is the only way it will perform well. Tiles out of DroneDeploy are about 4000x4000px at a 2in/px export.
Just thought of one thing that may influence how you tile. Does eCog require overlapping tiles? The tiles as downloaded from DroneDeploy are edged and stitch directly together…
Yes you are right, they need to have at least a 10% overlap