Author Topic: Mask Behavior  (Read 5803 times)


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Mask Behavior
« on: July 31, 2013, 07:30:57 PM »
So Im not sure if this is an isolated occurrence, but it seems to do it to me on multiple projects. Projects involve high altitude aerial imagery of a Hawaiian coastline. Since the ocean surface is moving and creates dynamic lighting effects, i use masks to exclude these regions from image alignment. This is done in photoshop using the intelligence selection tool which is much faster than using the included photoscan mask tools. in each photo, a new alpha channel is created from the selection and the image is saved as a tiff. Photoscan is able to import the masks using this procedure fine. The masks photo view shows water covered regions in black while the areas of modeling interest are shown in white. All my control points are in place, images are aligned and the point cloud is optimized. since i don't really care about building a mesh, i usually just select all the photos and click build depth. this works fine as well. After i have depth maps i have the option of exporting a DEM. here is where i run into problems, if i export a DEM or and orthomosaic without resetting the masks for all the images, the DEM and ortho are clipped inversely to how they are being used. By this i mean that the masks work fine for image alignment by excluding the regions i don't want, i can tell because the point cloud model of the alignment points have no trace of points in ocean regions, but when exporting DEM or orthomosaic the masks seem to be working inversely. I can work around this by resetting the masks for the entire group of photos, and then exporting, however if i need to do any last minute optimizations or realignments, i have to re-import the masks or create an inverted set and switch between them.

Alexey Pasumansky

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Re: Mask Behavior
« Reply #1 on: August 05, 2013, 03:25:50 PM »
Hello rival29,

DEM export is not affected by masks, because it is based on the mesh model.

But could you please confirm that orthophoto is generated incorrectly, when the masks are applied? We can not reproduce it on our side.
Best regards,
Alexey Pasumansky,
Agisoft LLC