Elements of visual interpretation
Topic: Remote Sensing, GIS and GNSS · NCERT: Class 11, Ch 6 "Introduction to Remote Sensing"
Meaning
The elements of visual interpretation are the clues an interpreter uses to identify objects in an image by eye. They fall into two groups:
- Image characteristics: tone or colour, texture, size, shape, shadow and pattern.
- Terrain characteristics: location and association, meaning where an object is and what it is found with.
These clues are usually used together, because one clue alone can mislead.
Example
In images of Delhi, Sansad Bhawan can be picked out by its round shape, the Qutub Minar by its long shadow, and factory complexes by their large size compared with houses. A railway shows up by its gentle curves, while a road has sharper bends.
Don't confuse with
- Digital image processing: identifies objects by computer work on pixel values, not by eye. It is not an element of visual interpretation.
Related concepts
- Aerial photograph
- Digital image
- Pixel
- Digital number
- Digital image processing
- False colour composite
- Visual image interpretation
- Tone
- Texture
- Shadow in image interpretation