Digital image processing
Also called: DIP · Topic: Remote Sensing, GIS and GNSS · NCERT: Class 11, Ch 6 "Introduction to Remote Sensing"
Meaning
Digital image processing (DIP) is using a computer to work on the digital numbers of an image. It is done to correct errors, improve the image and pull out useful information. Typical steps are correcting distortion, making features clearer and classifying land cover into classes such as forest, crops, water and built-up land. It needs both hardware and software. It can handle huge areas quickly and in the same way each time.
Example
NRSC, Hyderabad, calculates NDVI, which is (NIR − Red) ÷ (NIR + Red), from the pixel values of satellite images. This shows how healthy crops are and helps monitor agricultural drought across India.
Don't confuse with
- Visual image interpretation: identifying objects by eye, using clues such as tone, texture, shape and shadow. Digital image processing is not a visual interpretation technique.
Related concepts
- Aerial photograph
- Digital image
- Pixel
- Digital number
- False colour composite
- Visual image interpretation
- Elements of visual interpretation
- Tone
- Texture
- Shadow in image interpretation