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Elements of
Visual Image Interpretation
Qayssar Mahmood Ajaj
qayssarrsgis@gmail.com
Northern Technical University
Technical College Kirkuk
Elements of Image Interpretation
•Most of the time, many elements are used by an
image analyst without really thinking about them.
Elements of Image Interpretation
The elements are:
•Location
•Size
•Shape
•Shadow
•Tone and color
•Texture
•Pattern
•Height and depth
•Association
Elements of Image Interpretation
1- Location:
•Where is the object (x,y)?
•Survey or Global Positioning System (GPS)
• “Rectify” image to a base map or GPS coordinates
collected on the ground.
Elements of Image Interpretation
2- Size:
•Often an object’s distinguishing characteristic.
•Can make quantitative measurements like length, width,
perimeter, and area (this risky unless photography is
rectified).
•Objects of known size can be used to judge the size of
other objects.
•Thus, we can easily make qualitative descriptions like
small, medium, and large
Elements of Image Interpretation
Elements of Image Interpretation
3- Shape:
•Many natural and human-made features have unique
shapes.
•Often used are adjectives like linear, curvilinear, circular,
elliptical, radial, square, rectangular, triangular,
hexagonal, star, elongated, and amorphous.
Elements of Image Interpretation
Elements of Image Interpretation
4- Shadow:
•Shadow reduction is of concern in remote sensing and
photogrammetry because shadows tend to obscure
objects that might otherwise be detected.
•Shadows can also provide information on the height of
an object either qualitatively or quantitatively.
Elements of Image Interpretation
Jensen (2000)
Elements of Image Interpretation
5- Tone and color:
•Relative brightness or color of a feature
•These shades are called “tones”, and can be
qualitatively referred to as dark, light, or intermediate.
•Tone is related to the amount of light reflected from the
scene in a specific wavelength interval (band).
Elements of Image Interpretation
Jensen (2000)
Elements of Image Interpretation
•Color-combining techniques can be used to create color
composite images from individual bands.
•Humans can distinguish the difference between thousands
of subtle colors.
Elements of Image Interpretation
6- Texture:
•Texture refers to the arrangement of tone or color in an
image.
•Useful because Earth features that exhibit similar tones
often exhibit different textures.
•Adjectives include smooth (uniform, homogeneous),
intermediate, and rough (coarse, heterogeneous).
Elements of Image Interpretation
Elements of Image Interpretation
7- Pattern:
•Pattern is the spatial arrangement of objects on the
landscape.
•General descriptions include random and systematic;
natural and human-made.
•More specific descriptions include circular, oval, curvilinear,
linear, radiating, rectangular, etc.
Elements of Image Interpretation
Jensen (2000)
Elements of Image Interpretation
8- Height and depth:
•As discussed, shadows can often offer clues to the height of
objects.
•Descriptions include tall, intermediate, and short; deep,
intermediate, and shallow.
Elements of Image Interpretation
Elements of Image Interpretation
9- Association:
•This is very important when trying to interpret an object
or activity.
•Association refers to the fact that certain features and
activities are almost always related to the presence of
certain other features and activities.
Elements of Image Interpretation
Jensen (2000)
Thank you
Any Questions?