How to Properly Add an Image to the Activity

In the activity, I add an image through adding an ImageView and then adding my desired picture from the hdpi folder(its the only folder I'm allowed to select pictures from). However, there is one problem. I notice that when I add the picture and run it, there is an error. Basically I noticed that if the image is 72 pixels by 72 pixels, the app will run. However, when I compress it to 72 pixels by 72 pixels and run the app, the picture ends up being way too small.Is there any way I can just add the original picture to the Activity without compressing it all the way to 72 pixels by 72 pixels. By the way, I tried "enlarging" the 72 by 72 compressed picture by dragging on its corners, but it doesn't help.