[Exercises]
[Workspace]
Purpose:
The purpose of this lab is to experiment with a technique
of image contrast enhancement achieved by applying exponential
colormaps to images. This technique is useful for increasing contrast
in bright images.
Activities:
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Visualize the original over-bright image.
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Read and display the $DIP/data/cells-tissue-saturate.kdf image
using the operators User defined and Display Image.
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Glyphs:Input/Output:Data Files:User defined
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Glyphs:Visualization:Non-Interactive Display:Display Image
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Calculate the histogram and plot it using the Histogram
and Display 2D Plot operators.
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Glyphs:Data Manip:Histogram Operators:Histogram
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Glyphs:Visualization:Plot Display:Display 2D Plot
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Visualize the exponential color table.
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Print the contents of the $DIP/data/exp-256-lut.kdf color
table using the operator Print Data and File Viewer. Set
the Print Data parameters so that "Map Indexing" and "Map Data" are
selected.
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Glyphs:Input/Output:Data Files:User defined
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Glyphs:Input/Output:Information:Print Data
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Glyphs:Input/Output:Information:File Viewer
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Visualize the color table by plotting its values. Transfer the
data from the map segment to the value segment using the Copy to Value
operator, and plot it using the Display 2D Plot operator.
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Glyphs:Data Manip:Segment Operators:Copy to Value
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Glyphs:Visualization:Plot Display:Display 2D Plot
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This experiment shows three ways of enhancing the image using the
exponential colormap.
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Use the operator Display Image to display
the $DIP/data/cells-tissue-saturate.kdf image. Connect the colormap
file to the last entry of the Display Image operator ("Colormap
Image").
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Glyphs:Visualization:Non-Interactive Display:Display Image
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Insert the color table in the image file using the
operator Insert Segments. Insert the value segment of
the $DIP/data/cells-tissue-saturate.kdf file with the color table
file. Display it with Display Image.
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Glyphs:Data Manip:Segment Operators:Insert Segments
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Glyphs:Visualization:Non-Interactive Display:Display Image
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Use the image generated in the Part 3-B, and explicitly map the
data through the colormap using the operator Map Data. Calculate and
plot the histogram of this image and compare it with the original
image histogram.
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Glyphs:Data Manip:Map Operators:Map Data
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Glyphs:Visualization:Non-Interactive Display:Display Image
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Glyphs:Data Manip:Histogram Operators:Histogram
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Glyphs:Visualization:Plot Display:Display 2D Plot
Exercises
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Use the operator Data Object Info to see the differences in the
file contents of methods 2 and 3 above.
Glyphs:Input/Output:Information:Data Object Info
Glyphs:Input/Output:Information:File Viewer
Khoros Workspace
Execute the visual program c4s8contrast-exp.wk
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