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raw - pedestal cm in rows(128) and columns (512) using mask for square regions

Last version of common mode correction for pnccd

• Bill requested to correct all pixels.
• For each group of pixels common mode is evaluated cm for pixels defined by mask(1), applied for all in group

Best pnccd image correction algorithm for sxrx22915

• raw data - pedestal
• apply gain factor
• apply common mode correction in rows (128 pixel), mode=1
• apply common mode correction in columns (512 pixel), mode=4
• apply mask from status (bad pixels only)

Summary

• Image for raw data has horizontal and vertical stripes
• pedestals and gain, averaged for many images (common mode is averaged to zero), have vertical strips ONLY!
• So, common mode effect gives strong contribution in rows (horizantal strips)
• Median algorithms gives bands in image depending on regions of image brightness

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