how can I find a way to "mark" all objects

hi. I'm working on a project which is related to digital image processing, my question is how can I find a way to "mark" as like the "red mark" all objects and also how can I count it

[KALYAN ACHARJYA]

Marked on all contours or only shown in attched image?

[khaled bheri]

marked on all objects in the image and then count it

Answer 1

[Image Analyst]

regionprops(bw, ‘centroid’) then plot()

[khaled bheri]

thank you so much, but there are some objects not marked.so what should I do for these object

[Image Analyst]

It's problems like that why I suggested in the other answer to just count the area and divide by the area of one blob to get the blob count estimate. If you want to split apart blobs that are connected, you should read Steve's Image Processing Blog about watershed blob splitting. However it won't be perfect.