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Scaling how images are stitched together to make it look like images were recorded at the same speed

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Scaling how images are stitched together to make it look like images were recorded at the same speed

Hello,

I have an interesting problem that relates to stitching images of a moving object together into single images that will eventually be turned into an AVI. I have a camera that takes pictures at a certain rate, and I have an object (piston) that can move up and down at different speeds based on the rpm of the crankshaft. I want to be able to take in those sets of images taken at different rpms and stitch them together side by side. In addition, I want to be able to use these stitched images to create an AVI where the objects look like they are moving at the same speed. Is there some way i can manipulate the images being stitched together to achieve this? I have attached my current VI which stitches from 2-6 images together. 

Thanks,

Ryan

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Re: Scaling how images are stitched together to make it look like images were recorded at the same speed

Hi Ryan,

 

If you are looking for example code on how to stitch images together, I would recommend you to take a look at this post: https://forums.ni.com/t5/Example-Programs/Stitch-Images-Together-in-LabVIEW-with-Vision-Development-...

 

It shows you how you can stitch one image next to the other. 

 

As for creating the AVI file, you can use the function mentioned in this KB: http://digital.ni.com/public.nsf/allkb/0A4D5BF47FD3FF0186256E9A004FD671

You should be able to choose the rate of the AVI playback. 

 

I hope this helps! Let me know if I didn't understand your question correctly.

T. Le
Vision Product Support Engineer
National Instruments
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Re: Scaling how images are stitched together to make it look like images were recorded at the same speed

Thank you for the reply but I already have that functionaity. I am interested in scaling the speed at which the object moves in each video, so that the objects appear to move at the same speed.

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Re: Scaling how images are stitched together to make it look like images were recorded at the same speed

Hi,

 

I don't believe we have prebuilt functions that allow you to do this. However, something that you might want to do in order to have a video where the object appears to be moving at the same speed would be to decimate or add images to your video. Let's say you have a speed of reference for your object. You will need to decimate some frames from the images acquired with an object moving at a higher speed and you will need to add frames to the images acquired with an object moving at a slower speed. You can duplicate some frames to do that. 

 

Something else you could play with might be the playback rate. You could choose a playback rate proportional to the speed of the object if the frame rate is the same in every scenario. 

 

I hope this helps! 

 

 

T. Le
Vision Product Support Engineer
National Instruments
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