Smart Peoples, I have worked on performing custom google image search like entering text and it will display a list of images ,i got that file in JSON. I have already referred https://developers....

can any one please tell me how I can use google custom search in my iphone application to search images only. I tried it but it asks for 'cse' or 'cx' parameter. Please help.

Let's say I query for http://images.google.com.sg/images?q=sky&imgcolor=black and I get all the black color sky, how actually does the algorithm behind work?