I've been contributing to Alamy for a couple of months now and thankfully (knock on wood) have never had a QC rejection. This latest batch of images I'm processing has me wondering though if I'm upsizing enough.

My confusion lies in which size should I go by? There's a document size and an approximate file size within Photoshop and then there's the real file size reported by the operating system. I'm assuming I can disregard the size reported by the operating system so that leaves the two within PS from which to choose.

For instance the file I have open right now in PS has a document size of 17.2M and an approximate file size of 15.5M. So at the bottom of my screen I see:

Doc: 17.2M/15.5M

If I look at "Image Size," I see the 17.2M value. Sometimes I notice, however, that even within "Image Size" there are two values such as 17.2M/15.5M.

I've been going by the first value, but now I'm not so sure. Does anyone know why these values are different and which value I should look at to determine if it's been upsized enough for Alamy?

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Maybe it's a difference in versions of Photoshop, but with mine (v8), it's the number on the right that can be larger.

The number on the left represents the flattened file size, the one on the right the layered file size (on my photoshop). Of course Alamy is interested in the flattened file size.

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The first number, also the minimum accepted resolution would be between 16 and 17 MP, to confuse you a bit more.