Posted by
Robert Dougherty on
Aug 14, 2011; 5:37pm
URL: http://imagej.273.s1.nabble.com/is-there-a-way-to-change-the-calibration-bar-value-tp3683507p3683512.html
Jamal,
As far as I know, the process is:
1. Analyze/Calibrate to input your calibration curve
2. Image/Adjust Brightness and Contrast... to select the range of calibrated values to show in the image
3. Analyze/Tools/Calibration Bar... to make a new, RGB, image with the calibration bar included
A different approach is to convert your image to 32-bit with Image/Type/32-bit. Then you can use the mathematical transformations to map the pixel values into Relative Dose %. In your case, you would subtract 140 and multiply by 20, so that a pixel value of 140 is mapped to 0 and and pixel value of 145 is mapped to 5 and then 100. Use Process/Math/Subtract.... and then Process/Math/Multiply. After that, you can Adjust Brightness and Contrast and then create the calibration bar.
Bob
On Aug 14, 2011, at 10:03 AM, jamal jamal wrote:
> i think may be analyze/ calibrate..... but this option gives u a figure show the linearity or exponential relationship & so on......, so after we get this figure do u think is there a possible way to convert it to calibration bar ????because i have tried but it didn't work with me but sure based on my little experience in Image J
>
> Jamal
>
>> Date: Sun, 14 Aug 2011 08:13:30 -0700
>> From:
[hidden email]
>> Subject: Re: is there a way to change the calibration bar value???
>> To:
[hidden email]
>>
>> Jamal,
>>
>> Perhaps Analyze/Calibrate... ?
>>
>> Bob
>>
>> On Aug 14, 2011, at 4:14 AM, jamal jamal wrote:
>>
>>> i really thank you & appreciate your help Mr. Robert, but my problem i face is i want to add my own value to make calibration bar & in case i change the brightness or contrast some information will be lost in the image.
>>>
>>> i wanna add these values to make calibration bar, for example:
>>> Pixel value Relative Dose %
>>> 145 100
>>> 144.5 90
>>> 144 80
>>> 143.5 70
>>> 143 60
>>> 142.5 50
>>> 142 40
>>> 141.5 30
>>> 141 20
>>> 140.5 10
>>>
>>> i measured the Pixel value from Computed Tomography ( CT) Image & i want make calibration bar corresponding to these value.
>>> as u can see it's linear relationship & i wanna make these value as calibration bar to read other images.
>>>
>>>
>>> please inform me if u have an idea how to solve this problem
>>>
>>> i thank u again for response
>>>
>>> yours
>>> Jamal
>>>
>
Robert Dougherty, Ph.D.
President, OptiNav, Inc.
1414 127th Place NE #106
Bellevue, WA 98005
(425)891-4883
FAX (425)467-1119
www.optinav.com
[hidden email]