Page 40 - DENOISE projects professional - User Manual

On the right hand side are the same 3 buttons but for controlling light frames.
Dark frames – what are they?
A dark frame is a shot of sensor noise from a covered sensor. To shoot a dark frame,
cover the lens with an opaque object, or alternatively use the lens cap, and take a photo
of the dark noise.
It is important to use the same settings (exposure and operating temperature) when
taking a dark frame – ideally, take the normally lit photo and immediately after a dark
frame, so that the camera’s temperature doesn’t change too much.

Original image – Dark frame – Calibrated image

On the left we see the original image that is disturbed by the sensor’s dark noise.
The dark frame is in the middle, that is, the dark noise. The prominent interface is easily
recognizable by the lighter pixels, which are also easily seen in the original image. This
disturbance is usually caused by a sensor micro defect.
The picture on the right is the corrected (calibrated) image, with help from the dark
frame.

There are 4 parameters for dark frame correction settings:
(a) Iteration
Iteration shows the number of cycles of the dark frame correction algorithms. These
correction processes work very accurately. A high iteration value improves the precision
but probably generates a softer result.
(b) Threshold
The threshold determines the minimum brightness of the dark frame, so that a correction
for the respective pixel can occur.
(c)Correction radius

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