Question about sRGB color profiles

[Ben321]

I have a camera who's color profile is called sRGB and Gimp has its own color profile called sRGB. When I load a picture from my camera into Gimp, it asks me to keep or convert. Depending on which I pick (keep original sRGB color profile, or convert to Gimp's sRGB) the image DOES LOOK DIFFERENT. This tells me that the color profiles are not identical. I thought sRGB was the name of an international standard for converting linear values (as recorded by your camera's image sensor) into perceptual values (the values between 0 and 255 are proportional to the human eye's perception of brightness), in much the same way that things like USB is a standard (in this case a standard protocol for communication between a computer and a peripheral). So therefore anything using sRGB should be precisely compatible with anything else using sRGB, meaning that "keep" and "convert" should be exactly identical operations in this case. But clearly that's not what's happening.

Can anybody here explain why this is happening?

[Kevin]

I would suggest that, like USB, there are various versions of sRGB: https://ninedegreesbelow.com/photography...rison.html

[Ben321]

(07-06-2018, 09:50 PM)Kevin Wrote: I would suggest that, like USB, there are various versions of sRGB: https://ninedegreesbelow.com/photography...rison.html

Even so, why would converting to a new color space, or keeping the old color space make the image appear any different? If you keep the old color space, it also keeps the old pixel values, and uses the old color space to convert the pixel values to the signal that gets sent to the monitor. If you convert to the new color space, it also converts the pixel values, so that when processed through the color space the signals that get sent to the monitor produce the same visual appearance. Therefore, selecting "keep" or "convert" should never produce a different appearance on the monitor.

So something else must be going on. Any idea what is going on here?