The original in 16-bit mode is linear 12-bit acquire using Canon eos*dcs*3camera into Photoshop 15-bit space and then cropped.

Sharpening errors in gamma space:

1. overall luminance increases, see the eye areas and the white gauze around the numbers.
2. even with the weak sharpening noise increases considerably.

Linear space processing

1. Open the original linear higher bit-depth image.
2. convert to 8-bit mode.
3. apply USM at amount=100%, radius=1.0, thereshold=0.
4. apply inverse gamma 2.2.
5. save as jpeg using quality factor 4.

Gamma-space processing

1. Open the original linear higher bit-depth image.
2. apply inverse gamma 2.2.
3. convert to 8-bit mode.
4. apply USM at amount=100%, radius=1.0, thereshold=0.
5. save as jpeg using quality factor 4.