Hello Doug, Automatic crack detection is not an easy problem. A semi automatic classification will not find all cracks, because cracks can have very different appearances. A state of the art approach would be deep learning. At the German university TU Ilmenau they developed a robust neuronal network for the detection and classification of distresses in road surfaces. Here is a Link to one of the papers of this project:
https://www.tu-ilmenau.de/fileadmin/media/neurob/publications/conferences_nat/2017/Eisenbach-ATIM-2017.pdf Sincerely, Christoph >> Am 14.12.2019 um 07:05 schrieb Doug <[email protected]>: > > I have imported a set of drone pictures to QGIS. They show the streets in my > subdivision. I want to “record” the cracks in the pavement to be able to > compare them over time. I want to be able to segment the streets in > arbitrary lengths. For each segment, I want to “draw” the cracks (in layers) > to record where they are. Every year or two I will repeat the process. The > purpose is to be able to compare the set of cracks in successive snapshots to > see how the asphalt is holding up and identify underlying problems. I would > love to have some software to find the cracks for me and generate the crack > layer, if anyone knows of such software. > > First problem: I can trace the outline of the streets to generate a layer > which represents to road surface. Is there a way to slice that layer by > picking two points to “slice” the layer and then have two layers? And then > repeat the process so that I get the segments that I want? Alternatively, is > there a way to create a segment and “snap” to next segment so there is not > overlap or missing space? > > Second problem. Given that I have a layer representing a segment of the road > surface, can I “draw” the cracks for that segment such that every line in the > cracks layer is related (as in SQL) to the segment it reside in? > > Once I have the road surface segments, and the associated cracks, I can then > use SQL to generate all sorts of reports on the cracks: average and median > length, number of horizontal and vertical cracks, total crack length per road > surface segment (or square feet), etc. > > Thanks. > Doug > > > _______________________________________________ > Qgis-user mailing list > [email protected] > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
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