please give an idea how to check the resolution of an image during saving.... example i have to save an image that is not greater than 100dpi....so if the user try to save greater than 100dpi there will be an alert message..
I think, you can not get DPI information with PHP. You can check the resolution with getimagesize() function.
getimagesize("-------image url------ or image.jpg") Thats it. we can get allll the information about that image.