Added the ability to scan with a resolution of 0.25 mm

I set the maximum resolution to 0.5 mm for a long time ago, since then the 3D scanner and software have been greatly improved. Now I have added the ability to scan with a resolution of 0.25 mm. Of course, there are noises, but the sharpness increased significantly. File size too. But for small objects, such a mode may be in demand.