General > General high-speed discussion

Speed Calculations

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AIAS:
For the calculation of the speed accurately. First, take two successive images from your video. you can use "free video to jpg converter" to extract every frame. Second, download imageJ software and open the two images. you supposed to know the time interval between them. Then use the scale feature and draw a line for a known distance in the image. this stage determines how accurate your measurement is. it will give you how many pixels per inch/mm depends on your known distance. Finally, find the delta x and delta y of the moving object in pixels (you can easily get the pixel position by hovering the mouse in the image).

For example:
delta t between the two images is 0.001 second
delta x is 114 pixels
delta y is 0 >> object is moving horizontally.
scale: 228 pixels/mm

to find the distance: delta x / scale = 114/228 = 2 mm in 0.001 second
the speed then is distance/delta t = 2/0.001 = 2,000 mm/s    or    2 m/s

NiNeff:

--- Quote from: AIAS on July 23, 2019, 09:37:17 AM ---For the calculation of the speed accurately. First, take two successive images from your video. you can use "free video to jpg converter" to extract every frame.

--- End quote ---
The Chronos can already safe individual frames, no need for external  tools here. However a firmware upgrade might be required to do this.

AIAS:

--- Quote from: NiNeff on July 24, 2019, 09:03:48 AM ---
--- Quote from: AIAS on July 23, 2019, 09:37:17 AM ---For the calculation of the speed accurately. First, take two successive images from your video. you can use "free video to jpg converter" to extract every frame.

--- End quote ---
The Chronos can already safe individual frames, no need for external  tools here. However a firmware upgrade might be required to do this.

--- End quote ---

Yes. Also as a TIFF Format, but I found it less quality than h.254

skronstein:

--- Quote from: AIAS on July 25, 2019, 02:07:01 AM ---
--- Quote from: NiNeff on July 24, 2019, 09:03:48 AM ---
--- Quote from: AIAS on July 23, 2019, 09:37:17 AM ---For the calculation of the speed accurately. First, take two successive images from your video. you can use "free video to jpg converter" to extract every frame.

--- End quote ---
The Chronos can already safe individual frames, no need for external  tools here. However a firmware upgrade might be required to do this.

--- End quote ---

Yes. Also as a TIFF Format, but I found it less quality than h.254
[/quote

In what way was the quality lower for TIFF? The TIFF images are uncompressed, so they should be higher quality.
--- End quote ---

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