What is Track Length Slider for?

Development Asset Creation
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Hello,
I have a quick question. What is the Track Length Slider in SCENE tab for? Tried to slide it, but nothing seems to be changing at all. Can’t figure it out.

Thank you for replies.

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Hi filip.frycak

Track length can show you how are features propagated on images. one feature is always on more images and with slider you define how on much images is particular feature. This way you can inspect how good are features propagated.

Here you can see TRACK LENGT is set to 1 so it show dense feature point cloud

Track_Length_1.jpg

Second view show TRACK LENGTH set to 7, So you only see features that are on at least 7 images are shown in the viewport.

Track_Length_7.jpg

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I think this feature might need renaming.

“Track Length” isn’t exactly intuitive.

Perhaps something like “Feature Visibility” or “Feature Quality” ?

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Holy moly, I never bothered to look into it but should have!
I agree with ShadowTail about renaming.
How about: Images per feature?

And would it be possible to add a button “select visible” and another one “delete unselected”? :smiley:

Oh and then could you add a slider for “reprojection error”? :sunglasses:

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Ah, now I see. Well, useful tool. Thank you for answers.

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ShadowTail wrote:

I think this feature might need renaming.
“Track Length” isn’t exactly intuitive.
Perhaps something like “Feature Visibility” or “Feature Quality” ?

This term going from Computer Vision discipline. And “industrial” standard for its definition.

For example, if your camera not aligned but you know you have same feature on other images, this mean software “lost track”. And you can “recover” track with manual tie point.

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Now I can understand what you guys are talking about - and add my pennyworth.

Agree - track length is a name that caused me much misled puzzling.

I suggest ‘Average commonality of Features’ or (modifying Gotz’s) ‘Average Images per Feature’. This is UI specialists’ work - researching the perfect name for a function.

It’s related to settings in Inspect, using names like connectivity and consistency:

‘Component connectivity. Minimal connections with neighboring cameras/images.’

‘Feature consistency stands for minimal consistency of a feature. The number of cameras to be connected during the inspection process.’

Are these different concepts, or just inconsistent use of names?