Calibrating an array of grayscale pixel data 
Author Message
 Calibrating an array of grayscale pixel data

If I obtain an array from a grayscale picture which shows the
grayscale pixel values from 0-255, how do I calibrate this onto
another array so I can use the new data within an equation. For my
project each value of grayscale is equivalent to a temperature. For
example the value of intensity 20 is equivalent to 2380K, 40~1920K How
can I do this. Please help!


Fri, 24 Jun 2005 17:35:19 GMT  
 Calibrating an array of grayscale pixel data
Hi,

I'm sorry I didn't reply to your original thread, like I said.

If you have a 2d array of 8-bit values, make two for loops inside each
other. For each value, do the calibration operation you like to do. The
fastest way is to make a 1d array of values outside the two for loops, and
in the two for loops, look each gray scale value up in the 1d array.

If you are looking up the original values from the bitmap in the lookup
table of the bitmap, you could modify the original lookup table to reflect
the calibrated values. This will save processor time.

Hope it helps,

Wiebe.


Quote:
> If I obtain an array from a grayscale picture which shows the
> grayscale pixel values from 0-255, how do I calibrate this onto
> another array so I can use the new data within an equation. For my
> project each value of grayscale is equivalent to a temperature. For
> example the value of intensity 20 is equivalent to 2380K, 40~1920K How
> can I do this. Please help!



Fri, 24 Jun 2005 18:00:28 GMT  
 Calibrating an array of grayscale pixel data

Quote:
> If I obtain an array from a grayscale picture which shows the
> grayscale pixel values from 0-255, how do I calibrate this onto
> another array so I can use the new data within an equation. For my
> project each value of grayscale is equivalent to a temperature. For
> example the value of intensity 20 is equivalent to 2380K, 40~1920K How
> can I do this. Please help!

If the relationship between int8 pixel value and the temperature is
linear, you can do this pretty easily in the intensity graph.

The intensity graph takes a 2D array of numerics and maps them to colors
through the Z Scale.  The Z Scale defaults to displaying the numbers as
is, but by using the Offset and Multiplier for the Z scale, you can give
a linear function to map the pixel values to another numeric range.

Greg McKaskle



Sat, 25 Jun 2005 11:52:13 GMT  
 
 [ 3 post ] 

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