The Getty Images subsidiary said Tuesday the new payment structure is based on the contributor's output during the previous year rather than the total images sold in a lifetime.

The previous payment system allows contributors to earn more and get higher royalty when their photos are downloaded many times. Exclusive contributors get a higher percentage of sales.

Under the new system, earnings are based on the contributors' sales last year. Sellers of larger images also get higher royalty rates.

Contributors who don't sell exclusively will get a maximum 20 percent royalty instead of a minimum 20 percent royalty in the previous payment scheme. This will affect the royalties of contributors who uploaded photos many years back but who are now less active in contributing photos.

Some contributors see the new payment system as more favorable because quality will be more rewarded than the number of times a photos has been downloaded by customers. Getty Images will also be licensing higher quality works translating into higher revenues for photographers, according to Kelly Thompson, iStock's chief operating officer.

Thomson denied claims that contributors will see their earnings dropped saying contributors are miscalculating by excluding the peak selling months of September, October, November and December in their computations.

"We expect to see our total royalty payout increase by more than 30 percent next year, from $1 7-million per week to well over $2 million per week. Make no mistake, the total amount of money iStockphoto contributors are making is going up," Thomson was quoted by Cnet.com.