Color Models part 2-Digital Image Processing-Lecture Slides, Slides of Digital Image Processing

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HSI values corresponding toRGB color cube

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Conversion between RGB andHSI models

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Pseudocolor image processing ^ Goal:^ To

highlight^

various^ areas

or^ objects

in^ a

monochrome image with different colors so that theyare clearly visible and identifiable  The colors are assigned according to a specifiedcriterion, e.g. the gray level (intensity) properties ofthe image  Approaches for Pseudo color imaging are: ^ Intensity slicing and color coding ^ Gray-level to color transformations  Also known as false color image processing

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Pseudocolor image processingIntensity slicing (density slicing) and color coding ^ Based on 3D representation of intensity function^ ^ f(x,y) = l (3 coordinates: x,y,l) ^ Steps^ ^ M^ planes defined by

f(x,y) = l, i = 1,…,Mi

( l= 0:^0

the xy plane, I

= L-1 ) are used to slice the 3D M function into

M+1^ regions

R^ , k = 0,…,Mk^ ^ Assign color c

to the (x,yk^ k^

) at regions Rk^

:k

f(x^ ,y^ ) = c^ k^ k^ k

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Intensity slicing and color coding:Geometric interpretation

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Intensity slicing and color coding:Example

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Intensity slicing and color coding: Example

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Pseudocolor image processingGray level to color transformations Idea: Perform three independent transformations on thegray level of any input pixel and combine the three results

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Pseudocolor image processingGray level to color transformations Airport x-ray scanning system: Example of Color transformationsused in previous example

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Pseudocolor image processingPseudocolor coding approach with severalmonochrome images^ ^ Combine several monochrome images into a singlecolor composite^ ^ Often applied in multi-spectral image processing (differentmonochrome images acquired by different spectral bands)

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Reading assignment ^ Sections^ ^ 6.1: Color fundamentals^ ^ 6.2: Color models^ ^ 6.3: Pseudocolor image processing