Dept. of Geospatial & Space Technology

University of NairobiB. Sc. (Civil Engineering)

1.1. Concept of image interpretationConcept of image interpretation

2.2. Procedures of InterpretationProcedures of Interpretation

3.3. Interpretation ElementsInterpretation Elements

4.4. Interpretation KeysInterpretation Keys

5.5. Applications of Image Applications of Image

InterpretationInterpretation

FCE 552: Engineering Survey IV

Image Interpretation

Dept. of Geospatial & Space Technology

University of NairobiEngineering Surveying IV

Concept of Image Concept of Image InterpretationInterpretation

FCE 552: Engineering Survey IV

Dept. of Geospatial & Space Technology

University of NairobiEngineering Surveying IV

FCE 552: Engineering Survey IV

The Remote Sensing The Remote Sensing ProcessProcess

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

To extract qualitative and quantitative information To extract qualitative and quantitative information

from imagery about the from imagery about the shape, location, structure, shape, location, structure,

characteristics, quality, condition, relationshipcharacteristics, quality, condition, relationship of of

and between objects using human knowledge.and between objects using human knowledge.

Objective of Image Objective of Image InterpretationInterpretation

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Information from Information from ImageryImagery

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Human Interpretation vs Human Interpretation vs Computer based Computer based InterpretationInterpretation

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Procedures of InterpretationProcedures of Interpretation

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Procedures of Procedures of InterpretationInterpretation

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Image Classification involves assigning all pixels in the Image Classification involves assigning all pixels in the

image to particular classes or themes (e.g., water, image to particular classes or themes (e.g., water,

coniferous forest, deciduous forest, coniferous forest, deciduous forest, maizemaize, wheat, etc.). , wheat, etc.).

The resulting classified image is comprised of a mosaic of The resulting classified image is comprised of a mosaic of

pixels, each of which belong to a particular theme, and is pixels, each of which belong to a particular theme, and is

essentially a thematic "map" of the original image.essentially a thematic "map" of the original image.

Image ClassificationImage Classification (1)(1)

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Information Classes and Spectral ClassesInformation Classes and Spectral Classes::

Information classesInformation classes are those categories of interest that are those categories of interest that

the analyst is actually trying to identify in the imagery, the analyst is actually trying to identify in the imagery,

such as different kinds of crops, different forest types or such as different kinds of crops, different forest types or

tree species, different geologic units or rock types, etc. tree species, different geologic units or rock types, etc.

Spectral classesSpectral classes are groups of pixels that are uniform (or are groups of pixels that are uniform (or

near-similar) with respect to their brightness values in near-similar) with respect to their brightness values in

the different spectral channels of the data. the different spectral channels of the data.

The objective is to The objective is to matchmatch the spectral classes in the data the spectral classes in the data

to the information classes of interest. Rarely is there a to the information classes of interest. Rarely is there a

simple one-to one match between these two types of simple one-to one match between these two types of

classes. classes.

Image ClassificationImage Classification (2)(2)

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Interpretation ElementsInterpretation Elements

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Interpretation ElementsInterpretation Elements

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Interpretation KeysInterpretation Keys

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Elements of Tone/ColourElements of Tone/Colour

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Elements of Size & Elements of Size & ShapeShape

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Elements of TextureElements of Texture

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Elements of PatternElements of Pattern

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Elements of Height & Elements of Height & ShadowShadow

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Elements of Associated Elements of Associated RelationshipsRelationships

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Interpretation Keys for TreesInterpretation Keys for Trees

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Applications of Image Applications of Image InterpretationInterpretation

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Interpretation of Aster ImageInterpretation of Aster Image

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Colour CompositionColour Composition

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Image Interpretation – Land Image Interpretation – Land CoversCovers

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Image Interpretation – FloodsImage Interpretation – Floods

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Image Interpretation – WildlifeImage Interpretation – Wildlife

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Image Interpretation – VolcanoImage Interpretation – Volcano

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Image Interpretation – MineImage Interpretation – Mine

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Image Interpretation – Image Interpretation – EnvironmentEnvironment

Dept. of Geospatial & Space Technology

University of Nairobi

FCE 552: Engineering Survey IV

B. Sc. (Civil Engineering)

Image Interpretation – OceanImage Interpretation – Ocean