Just use find():
[rows, columns] = find(binaryImage);
rows and columns will be vectors of the rows and columns (matched up) of every single white pixel in your binary image.
Other than that I'm not sure what you want because of the two situations you stated: one where you said you want the boundaries (perimeters) and the other where you said you wanted the enclosed coordinates. Is it one or the other or both?
I'm also unsure exactly what "search within" and "search in" means. Search for what?
You have hundreds of blobs there. If you just want the pixels inside each blob, but not on the boundary itself, then call imerode() to eat away one layer of pixels from all blobs. What's left will be just the "inside".
