Unusual features in GRIP
Here are some of the features of GRIP which are not commonly found in software for processing photographs.
- Averaging images to reduce electronic noise
- Subtracting images to remove backgrounds or to detect changes
- Automatically correcting uneven backgrounds caused by vignetting or bad lighting
- Displaying camera raw data as an image, un-interpolated, so that defective pixels may be mapped.
- Measuring shapes
- Showing level profiles along straight or curved lines, for each colour band
- Grossly magnifying any part of an image, so the pixels can be seen
- Thresholding and automatically detecting objects within images and measuring them
- Displaying graphs of measurements as a function of the times when the photographs were taken (such times are read from the image metadata where available)
- Saving measurements as CSV or XML files
- Swapping channels between images to show changes in a colourful way
- Gnomonic projections and inverse projections to flatten images for combining them (eg, for making panoramas)
- Processing sequences of astronomical photographs to combine them and reduce background artefacts. This process is designed to cope with the stars having moved between photos because of the Earth's rotation.
- Estimating star magnitudes by comparison with reference stars.