That's because you do not know what HDR means…
HDR is two things, HR and D. HR because the light intensity in the real life go from a candela to a million. The D is to map that ridiculous range to a monitor that can mostly do 200 candela and is quite LR.
D is your tonemapper, the simpliest and oldest is just to saturate when the color intensity is over 1. Modern tonemapper try to compress a HR range to keep more details, using some kind of curve, often based on the image mean intensity and more modern even use the histogram. Because we are funky and the cinema use tricks that are century old to have more pleasant colors in film, we also add filmic tonemapper to emulate the response of the fine tuned photographic film. To use it or not depends if you want the game to be like looking at a movie or play it like you are in the real life.
Now, to D work properly, you need a correct HR first, and that's not possible on Wii. Lighting and blending have to accumulate in what we call the linear space. But because the human eyes do not have a linear response to intensity ( we are better at low intensity ), textures are in gamma space ( a space more or less linear in regards to the human perception of brightness and it was also near to the phosphors answer in old CRT, cool ). It means that a GPU have to revert it back in linear compute lighting and blending then convert it back to gamma before displaying the picture and the Wii GPU does not do that at all.
So, the Wii does not have a correct lighting pipeline and does saturate colors in a surface that cannot be more than 1, so their is no way that from a LR picture you can have a better LR picture that would looks like made from an HR source…
HDR is two things, HR and D. HR because the light intensity in the real life go from a candela to a million. The D is to map that ridiculous range to a monitor that can mostly do 200 candela and is quite LR.
D is your tonemapper, the simpliest and oldest is just to saturate when the color intensity is over 1. Modern tonemapper try to compress a HR range to keep more details, using some kind of curve, often based on the image mean intensity and more modern even use the histogram. Because we are funky and the cinema use tricks that are century old to have more pleasant colors in film, we also add filmic tonemapper to emulate the response of the fine tuned photographic film. To use it or not depends if you want the game to be like looking at a movie or play it like you are in the real life.
Now, to D work properly, you need a correct HR first, and that's not possible on Wii. Lighting and blending have to accumulate in what we call the linear space. But because the human eyes do not have a linear response to intensity ( we are better at low intensity ), textures are in gamma space ( a space more or less linear in regards to the human perception of brightness and it was also near to the phosphors answer in old CRT, cool ). It means that a GPU have to revert it back in linear compute lighting and blending then convert it back to gamma before displaying the picture and the Wii GPU does not do that at all.
So, the Wii does not have a correct lighting pipeline and does saturate colors in a surface that cannot be more than 1, so their is no way that from a LR picture you can have a better LR picture that would looks like made from an HR source…