Finding the variation in movement of particular colour in series of image

Overview:

Camera takes a picture of top view of an object (black circular disc with colour marked center - static). Each time it takes a picture of it, I need to find the variation of displacement of the center of the object.

Questions:

How to find that particular dot?

Can I find variations in micron level?

What kind of resolution of picture is needed for this requirement?

What format of picture will be easy?

Any other tips?

Thanks in advance!

[KALYAN ACHARJYA]

object (black circular disc with colour marked center).

Can you share one image?

[Prasanna Venkatesh]

@ Kalyan Acharjya

Sorry. It might take time. May I know why picture is needed? Is it possible to do the above?

[KALYAN ACHARJYA]

Camera takes a picture of top view of an object (black circular disc with colour marked center).

Image might help to better undestand the question.

[Prasanna Venkatesh]

@ Kalyan Acharjya

Ya. Sure. I will try to do it asap.

Answer 1

[Prabhan Purwar]

Assumption: I am assuming the camera to be stationary and object moving.

You can make use of imfindcircles() function to detect the center of the circular object along with radius.

• https://www.mathworks.com/help/images/ref/imfindcircles.html?searchHighlight=imfindcircles&s_tid=doc_srchtitle (Documentation)

For a more detailed insight into the topic, please refer to Image Segmentation Tutorial and Detecting circular object blog linked below.

• https://www.mathworks.com/matlabcentral/fileexchange/25157-image-segmentation-tutorial (Image Segmentation Tutorial)
• ·https://blogs.mathworks.com/steve/2012/09/04/detecting-circular-objects-in-images/ (Detecting circular object)

[Prasanna Venkatesh]

@ Prabhan Purwar

Thanks! But, Why would I need to find the center of circle, when it is already marked with different colour? My question is, Can I detect the motion of coloured mark in microns? What are all needed to do that.

I think 'Image segmentation' might be useful

[Prabhan Purwar]

Following is a link to coloured object detection based on spectrum selection

• https://www.mathworks.com/matlabcentral/fileexchange/40022-how-to-detect-and-track-red-colored-object-in-live-video?focused=6513817&tab=function (Coloured object detection)

Please attach Image, it may help to provide you a specific solution.