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Topics - chrisd

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General / Angle between photos/cameras?
« on: May 27, 2018, 11:56:44 PM »
Does anyone know of a current function to get the angle between any two photos/cameras? I'm using Photoscan Standard but I would be interested to know if its possible to do in Pro.

I'll put it up as a feature request if there's not already a way to generate that info.

General / Laser (or other) noise projection? Regular pattern VS noise?
« on: February 18, 2018, 03:00:07 AM »
I tried a search for this topic and for noise projection in general, nothing after 2013 or so comes up. Most of the laser projectors I've seen advertised are far too dim to be useful (200 lumens approx). I'm speaking of the type that project color images or video.

I'm not opposed to using a fixed color/pattern providing the point or line density is high enough to useful. The projected pattern should be bright enough to provide contrast with typical indoor lighting.

I do not know if noisy pattern provides advantages over a regular pattern. Hopefully I can learn more on that.

General / Exporting dense cloud from chunks, maintain scale?
« on: May 22, 2017, 08:53:29 PM »
I see its possible to to use the scale of a single chunk to force the other chunks to fit the same scale in alignment.

If I wish to do the alignment in another application, is there a way to ensure the dense clouds from each chunk will all be exported at the same scale?

General / Controlling camera setup (rig?) to establish repeatable scale
« on: February 27, 2017, 07:02:17 PM »
EDIT, changed thread title to something more specific

- I understand the common way to get my scan size to match the actual size real world units.
- I'm using Photoscan Standard
- Subjects are objects, not topographical

Lets say I can't measure a reference distance on my subject ... Is there any way to establish a scaling value based on other info?

One thing I have considered is using two (or multiple) cameras a fixed distance apart, so there would be groups of pairs (or multiples) at each shooting position. I don't know the math involved so I am not sure there would be any advantage to this.

Would I be able to determine some scale that I could reliably use in all cases where the cameras are a specific distance apart at each shooting location?

Or, does anyone have other methods?

General / Pair preselection or Generic
« on: February 24, 2017, 11:54:40 PM »

I am using Photoscan Standard version 1.3.0 build 3772. The documentation for this version indicates a choice of Pair preselection or Generic. However, the dialog shows only a check box for Generic with no mention of Pair preselection.

Can I assume that unchecking Generic results in Pair preselection?

General / Noise Projection and shiny surface?
« on: December 31, 2016, 12:48:05 AM »
I'm curious if anyone has used noise projection to capture moderately shiny and untextured surfaces?

General / Terraced effect from aerial images, causes?
« on: February 22, 2016, 11:02:02 PM »
The attached pic show a terraced or stepped effect from aerial images. Unfortunately I don't have the original images to test them in Photoscan. I know a DJ Phantom was used to capture the images, but don't have info about the specific camera. The mesh was not generated by Photoscan.

I looked at few cross sections through the mesh and there are small but abrupt differences in elevation corresponding to the visible change in the triangulation. There is some variation in elevation within each "terrace".

From searching other posts on the forum, it appears it can be attributed to not having enough images with sufficient overlap between images, or perhaps, the camera angle is highly oblique to the surface.

Are there other factors that might contribute to this issue?

I know since I can't supply any of the captured images or additional info any input will be generalized ...

General / Accuracy measurement?
« on: June 26, 2013, 04:04:16 PM »

I searched the manual, forum and the wiki and have some good information about best practices for using the software and camera but did not see anything that answers my question below.

Is there a method that can predict the accuracy for an object (an "approximate" range of values is OK) that could apply to future situations without loading the images into Photoscan to get the values?


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