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I often have trouble estimating best image pixel size to large centimeter size, without causing much loss of quality.
Today is no different. A client wants a chosen image from shutterstock on his wall. (as wallpaper). The wall is 6680x1200mm
I can see on shutterstock the pixel size from the image. But how can I estimate if the pixel size is high enough for the size of the wall, without buying the image? Can I calculate what the minimum pixel format should be? If so, how can I do that?