How to count the number of detected objects in the image?

I Want to develop an application that can count the number of objects in an images. It's not important to know the shape of the objects. I just need the information of how many objects in an image.

An i want that it can be implemented in many images, is it possible?

How to do that?

Here is my code :

a=citra1;  
a_citra_keabuan = rgb2gray(a);
threshold = graythresh(a_citra_keabuan);
a_bww = im2bw(a_citra_keabuan,threshold);
a_bw = bwareaopen(a_bww,30);
se = strel('disk',2);
a_bw = imclose(a_bw,se);
a_bw=~a_bww;
[labeled,numObjects]=bwlabel(a_bw);

The "numObjects" shows the number of the detected objects in an images.

Here is the sample of the images

Images1 http://imgur.com/aWaNOxD

Images2 http://imgur.com/x5mgymo

Images3 http://imgur.com/mhmHPT1

Images4 http://imgur.com/An8EX9q

Images5 http://imgur.com/dEl8NTF