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5.4 Format
These are operations which change an object's format in some way.
- Convert_format_to
- These items change number representation. For images, they change the
meaning and number of bits in the file. For other objects they trim
the range and accuracy of value.
- Scale_to_byte
- This searches an object for the minimum and maximum value, calculates
a linear (scale and offset) transformation which will move the min and
max to the range 0-255, and returns the scaled object.
- Convert_to_matrix
- This examines the object and tries to build a matrix from it. This
will only work for small images: it is very inefficient to represent
an image as a matrix.
- Convert_to_image
- This examines the object and tries to build an image from it.
- Matrix_from_colour_chart
- This takes a trimmed image of a colour chart (a rectangular grid of
coloured squares), measures the average pixel value in the centre 50%
of each square, and returns a matrix of the measured values. It
assumes the chart is 6
4 patches (the size of a Macbeth
Color Checker Chart): for other size charts, open the row and change
the dimensions.
- Colour_chart_from_matrix
- This takes a matrix of colour measurements and builds a synthetic
chart image. It assumes the chart is 6
4 patches (the
size of a Macbeth Color Checker Chart): for other size charts,
open the row and change the dimensions.
- Colour_from_image
- This takes the average of each band of an image and builds a colour
object for that average.
- Colour_from_image
- This builds a small image from a colour object.
- Decompose
- This examines a compound object and tries to break it into a list of
smaller objects. A matrix becomes a list of vectors, an
band image becomes a list of
1 band images, and so on.
- Compose
- This takes a list of objects and tries to join them together to
make a compound object. A list of numbers become a vector, a
1 band images become a
band image, and so on.
Next: 5.5 Histogram
Up: 5. Image processing menus
Previous: 5.3 Filter
  Contents
John Cupitt
2003-07-21