I have a 6 MP camera. I would like to provide pictures taken with this camera as downloaded artwork, however when I upsample a picture at 300 dpi to 11x14 the file size is 50 MB, way too large to expect someone to download. Is there a means of compression that I can use that will not denigrate the quality of the picture? As a general rule how much upsampling is sufficient to make sure the end user has as good an image as the source they are buying? Is 300 dpi too much for printing? What file format would be the best for use by an amateur art collector that doesn't know a lot about photography and printing; they just want to buy the picture to hang on their wall? What's the best way to sell these images online? Many thanks for your input.

Rick

Why resample the image in the first place?

Most online stock image sources sell Jpegs for downloading and maybe Tiffs on request.