Usage

Wipe is able to detect - and correct for - various complex calibration problems and unwanted artificial signal sources. In addition to a gradient removal routine, it is to detect and model vignetting issues (including over-correction), as well as bias/darks issues.

Common calibration issues include;

• Vignetting manifests itself as the gradual darkening of a dataset towards the corners. It is ideally addressed through flat frame calibration when stacking.
  
• Amp glow is caused by circuitry heating up in close proximity to the CCD, causing localised heightened thermal noise (typically at the edges). On some older DSLRs and Compact Digital Cameras, amp glow often manifests itself as a patch of purple fog near the edge of the image.

Unwanted or artificial signal may include;

• Light pollution, moon glow, airglow, zodiacal light and gegenschein gradients are usually prevalent as gradual increases (or decreases) of background light levels from one corner of the image to another. Most earth-based acquisitions contain a gradient of some form, as even under pristine skies such gradients are prevalent.
  
• Signal bias is a fixed background levels which, contrary to a gradient, affects the whole image evenly. Most non-normalised datasets exhibit this.
  
• Amp glow is faint "glow" near one or more edges caused by local thermal noise from heat-dissipating electronics.

While highly effective, it is important to stress that Wipe's capabilities should not be seen as a replacement or long-term alternative to calibrating your datasets with calibration frames; calibrating your dataset with flats, darks and bias masters will always yield superior results. Flats in particular are the #1 way to improve your datasets and the detail you will be able to achieve in your images.