Topics

1

Camera Calibration / Can I place tie points by hand?

« on: August 13, 2025, 04:48:36 PM »

I'm using Metashape standard.  For aligning some difficult image stets it would help if I could place tie points manually by clicking on images.  Is that possible?

2

Camera Calibration / A better way to calibrate cameras

« on: February 02, 2024, 08:52:50 PM »

Many panoramic photographers now use motorized robot rotators that can position a camera with milli-degree accuracy. These devices turn the camera around a fixed point, so are not suitable for acquiring images for photogrammetry. However they do make possible a new way of calibrating cameras and lenses, that is both more convenient and more accurate than traditional methods based on special targets. In brief, one takes a series of photos of any suitably detailed large subject, turning the camera by a small angle between shots, and processes them with a panorama stitcher set up to estimate just the camera parameters, the pointing angles being given.
Suitable tools for this are the Fanotec Nodal Ninja Mecha robots and PTGui, the professional stitching software. Mechas cost little and are accurate enough.  PTGui works similarly to a sfm tool, identifying matching keypoints and aligning them by a kind of bundle adjustment. The estimation problem is simpler because the photos all have the same viewpoint; consequently the camera parameters are usually very accurate -- especially so when accurate view directions are provided a priori.
Unfortunately PTGui's lens model differs considerably from any of the ones supported by MetaShape, so there is no possibility of a direct transfer of parameters. However, I think it would be worthwhile to explore possible ways to overcome this barrier, as the robot calibration method really is superior.

3

Camera Calibration / Using exported camera parameters

« on: February 02, 2024, 08:40:42 PM »

In my own software, I need to map 3D points to image coordinates using points and camera calibrations exported by MetaShape. To be sure I am doing this right, I would like to verify the mapping formulas that you use.  Is that information available? I am specifically interested in the frame and fish-eye camera models.

4

Feature Requests / Manual photo alignment in Standard edition

« on: June 22, 2014, 12:58:53 AM »

I have no budget for the Pro level Photoscan, nor do I need its many georeferencing features.  But I do think I deserve a chance to manually correct the situation when the automatic photo alignment fails. This is not uncommon in my experience on photos whose overlap, and visible features, I would judge as more than adequate for panorama stitching (which is my primary occupation and interest).   Even a very primitive way to guide the s/w to a valid alignment -- such as pointing out which edges of 2 images overlap -- would probably be enough; in other words the solution need not involve your "marker" system, use of which seems to be limited to Pro version.   Autodesk 'Photo on Recap 360' allows such manual "stitching" at the low-cost level, and I think Agisoft should also.