CMOS图像校准

https://diffractionlimited.com/calibrating-cmos-images/

Basic Calibration
Keep it simple – same basic math as for CCDs.

• Output Image = (Light – Dark) / Normalized (Flat – Flat-Dark)
• Take all calibration and light frames at the exact same sensor temperature, including flats.
• Use the exact same gain levels and sensor operating modes for all frames.
• Do not use bias frames.
• Do not use exposure scaling.
• Take dark frames matching your light frames.
• Take dark frames matching your flat-field frames.
• Use lots of frames.
• Calibrate your flats using matching master dark frames.
• Calibrate your lights using matching master dark frames.
• Try different flat-field exposure times (and flat-darks) and compare results quantitatively.
• Finally, as described above, if you like to reuse calibration frames for a period of time, be aware that large ambient temperature changes or even a simple firmware update could potentially change the camera characteristics. This may require reshooting calibration sets more frequently than you are used to.

Doug George
President/CEO and Lead Engineer
Diffraction Limited