how to determine if an image has an object or empty

i want to do shape detection however i was wondering if i would able to make the system able to determine if the image has an object or its an empty image. if yes, which method should i use? thanks in advance

[Image Analyst]

Please attach one image of each type, and tell us what you consider to be "an object" in the image.

http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer

[John D'Errico]

The issue of course is that only you know if something is of interest.

For example, suppose I take a picture where one pixel represents what I care about, with the rest of the image a flat field. Yes, the "object" is something really tiny.

Seeing the existence of an object is entirely in your definition of what is an object.

[kaz]

as it shows in the following figures, the first image has two objects detected, i want the system to define if the object was not detected as shown in image 2 so i can state conditions for it such as if the object 1 is not detected, then show (condition).

[Walter Roberson]

How should your code know if it is object 1 that is missing or object 2 that is missing? Are the objects always in the same place?

If you just want to know how many objects you have, then bwlabel() the thresholded image and look at the second output num of bwlabel()

Answer 1

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/243406-how-scan-an-image-fully-and-seperate-the-area-of-interest-using-matlab#answer_192657

Answer 2

[Image Analyst]

Try this, like Walter said:

[~, numberOfObjects] = bwlabel(binaryImage);