Thanks a lot everyone.
Let me tell you the method I found out to crop the suitable photos - I did so some months ago. In the initial stages I was finding it hard to crop to the set size required for the banner. My pictures are 3072 x 2000 something. So what I do is to first crop the area to 3000 x 300 if that is available in the subject. I use Microsoft Office Picture Manager for this purpose. After this is achieved, I go to resize image, then choose 50%. Now the image is reduced to 1500x150, which is the max. Sometimes I go for 2400 pixels which reduces to 1200 which is the minimum width required. Earlier I was choosing 1500 by which a lot of the good area was lost.
