Well of course a filter to blur the image won't improve it - not sure why you thought it would. The things you need to improve it are optical, not software. These are:
- Use a faster frame rate to reduce motion blur.
- White balance your camera to improve color fidelity.
- Use a smaller aperture (larger F/stop) to improve the depth of field.
- Use more light to reduce noise and improve colors.
- Use a better camera for obvious reasons.
- Use a better lens to reduce optical aberrations (spherical, distortion, coma, chromatic, etc.)
- Use better lighting, perhaps softboxes or umbrellas
Following my suggestions above will give you a better image than you can get with post processing a crummy image in MATLAB.
