Tone refers to the relative brightness or colour of objects in an image. Generally, tone is the
fundamental element for distinguishing between different targets or features.
Variations in Elements of Visual Interpretation tone also allows the elements of shape, texture, and pattern of objects to bedistinguished.Shape refers to the general form, structure, or outline of individual objects. Shape can be a very distinctive clue for interpretation. Straight edge shapes typically represent urban or
agricultural (field) targets, while natural features, such as forest edges, are generally more
irregular in shape, except where man has created a road or clear cuts. Farm or crop land
irrigated by rotating sprinkler systems would appear as circular shapes.
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Size of objects in an image is a function of scale. It is important to assess the size of a target relative to other objects in a scene, as well as the absolute size, to aid in the interpretation of that target. A quick approximation of target size can direct interpretation to an appropriate result more quickly. For example, if an interpreter had to distinguish zones of land use, and had identified an area with a number of buildings in it, large buildings such as factories or warehouses would suggest commercial property, whereas small buildings would indicate residential use.
Pattern refers to the spatial arrangement of visibly discernible objects. Typically an orderly repetition of similar tones and textures will produce a distinctive and ultimately recognizable pattern. Orchards with evenly
spaced trees, and urban streets with regularly spaced houses are good examples of pattern. Texture refers to the arrangement and frequency of tonal variation in particular areas of an image. Rough textures would
consist of a mottled tone where the grey levels change abruptly in a small area, whereas smooth textures would have very little tonal variation.
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Smooth textures are most often the result of uniform, even surfaces, such as fields, asphalt, or grasslands. A target with a rough surface and irregular structure, such as a forest canopy, results in a rough textured appearance. Texture is one of the most important elements for distinguishing features in radar imagery.
Shadow is also helpful in interpretation as it may provide an idea of the profile and relative height of a target or targets which may make identification easier. However, shadows can also reduce or eliminate
interpretation in their area of influence, since targets within shadows are much less (or not at all) discernible from their surroundings.
Shadow is also useful for enhancing or identifying topography and landforms, particularly in radar imagery.
Association takes into account the relationship between other recognizable objects or features in proximity to the target of interest. The identification of features that one would expect to associate with other features may provide information to facilitate identification. In the example given above, commercial properties may be associated with proximity to major transportation routes, whereas residential areas would be associated with schools, playgrounds, and sports fields.
Texture refers to the arrangement and frequency of tonal variation in particular areas of an image. Rough textures would consist of a mottled tone where the grey levels change abruptly in a small area, whereas smooth textures would have very little tonal variation. Smooth textures are most often the result of uniform, even surfaces, such as fields, asphalt, or grasslands. A target with a rough surface and irregular structure, such as a forest canopy, results in a rough textured appearance. Texture is one of the most important elements for distinguishing features in radar imagery.
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fundamental element for distinguishing between different targets or features.
Variations in Elements of Visual Interpretation tone also allows the elements of shape, texture, and pattern of objects to bedistinguished.Shape refers to the general form, structure, or outline of individual objects. Shape can be a very distinctive clue for interpretation. Straight edge shapes typically represent urban or
agricultural (field) targets, while natural features, such as forest edges, are generally more
irregular in shape, except where man has created a road or clear cuts. Farm or crop land
irrigated by rotating sprinkler systems would appear as circular shapes.
.jpg)
Size of objects in an image is a function of scale. It is important to assess the size of a target relative to other objects in a scene, as well as the absolute size, to aid in the interpretation of that target. A quick approximation of target size can direct interpretation to an appropriate result more quickly. For example, if an interpreter had to distinguish zones of land use, and had identified an area with a number of buildings in it, large buildings such as factories or warehouses would suggest commercial property, whereas small buildings would indicate residential use.
Pattern refers to the spatial arrangement of visibly discernible objects. Typically an orderly repetition of similar tones and textures will produce a distinctive and ultimately recognizable pattern. Orchards with evenly
spaced trees, and urban streets with regularly spaced houses are good examples of pattern. Texture refers to the arrangement and frequency of tonal variation in particular areas of an image. Rough textures would
consist of a mottled tone where the grey levels change abruptly in a small area, whereas smooth textures would have very little tonal variation.
Smooth textures are most often the result of uniform, even surfaces, such as fields, asphalt, or grasslands. A target with a rough surface and irregular structure, such as a forest canopy, results in a rough textured appearance. Texture is one of the most important elements for distinguishing features in radar imagery.
Shadow is also helpful in interpretation as it may provide an idea of the profile and relative height of a target or targets which may make identification easier. However, shadows can also reduce or eliminate
interpretation in their area of influence, since targets within shadows are much less (or not at all) discernible from their surroundings.
Shadow is also useful for enhancing or identifying topography and landforms, particularly in radar imagery.
Association takes into account the relationship between other recognizable objects or features in proximity to the target of interest. The identification of features that one would expect to associate with other features may provide information to facilitate identification. In the example given above, commercial properties may be associated with proximity to major transportation routes, whereas residential areas would be associated with schools, playgrounds, and sports fields.
Texture refers to the arrangement and frequency of tonal variation in particular areas of an image. Rough textures would consist of a mottled tone where the grey levels change abruptly in a small area, whereas smooth textures would have very little tonal variation. Smooth textures are most often the result of uniform, even surfaces, such as fields, asphalt, or grasslands. A target with a rough surface and irregular structure, such as a forest canopy, results in a rough textured appearance. Texture is one of the most important elements for distinguishing features in radar imagery.
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