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Temperature look-up table
05-14-2014, 03:43 AM
Post: #1
Temperature look-up table
In the SDK use's manual, page 64, it says that "the table translates absolute image pixels to temperature", and it also says than the table is 1-dimensional array(the image pixels is 2-dimensional array), so what is the progress between this translate?Thanks for answering me!
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05-15-2014, 04:58 AM
Post: #2
RE: Temperature look-up table
The table gives a correspondence between levels and temperature which can be expressed by the formula below.
Temperature (i,j) = LUT [Abs_pixel(i,j)]
LUT is a just a function that applies to a pixel value.
There is no possible confusion between the dimension of the lookup table, and the image dimension.
Raphael.
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05-15-2014, 12:46 PM
Post: #3
RE: Temperature look-up table
(05-15-2014 04:58 AM)RDanjoux Wrote:  The table gives a correspondence between levels and temperature which can be expressed by the formula below.
Temperature (i,j) = LUT [Abs_pixel(i,j)]
LUT is a just a function that applies to a pixel value.
There is no possible confusion between the dimension of the lookup table, and the image dimension.
Raphael.



Thank you very much! I realized that LUT is a projection, but didn't know how. Now I understand it clearly.

But I have one more question and any comments you care to make would be more than welcome.

We know that GetImage function returns the pixel values, in the SDK's samples, I can only get a Grey Scale Image through these pixel values, so how can I get the Pseudo-color Image? In other words, how can I build the color look-up table?
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05-16-2014, 01:41 AM
Post: #4
RE: Temperature look-up table
In principle, you use the same kind of table of correspondence, except that the final result is a color.
You first define a range, Min_Temp and Max_Temp for instance, with a given number of colors, 256 for instance.
Then, each temperature (rounded) between these two limits is represented by a color. Typically, these are based on Red Green Blue coefficients, each of them coded on 8 bits.
Try change the font color in a PC application, and go to custom color. You should be able to see the color resulting from these different RGB coefficients.
RDanjoux.
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05-16-2014, 07:50 AM
Post: #5
RE: Temperature look-up table
(05-16-2014 01:41 AM)RDanjoux Wrote:  In principle, you use the same kind of table of correspondence, except that the final result is a color.
You first define a range, Min_Temp and Max_Temp for instance, with a given number of colors, 256 for instance.
Then, each temperature (rounded) between these two limits is represented by a color. Typically, these are based on Red Green Blue coefficients, each of them coded on 8 bits.
Try change the font color in a PC application, and go to custom color. You should be able to see the color resulting from these different RGB coefficients.
RDanjoux.


Thank you very much! I'm working on it~~
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