http://imagej.273.s1.nabble.com/16-bit-image-visualization-tp5018625p5018648.html
Hi Jeremy- I realize that you can only see 8 bits, but you should be able to visualize 8 bits worth of data from different ranges of the 65000 gray levels in the image. I can easily look at 8 bits of bright pixels, but I can’t look at 8 bits of medium brightness or 8 bits of just over background information. The dim stuff is overwhelmed by the saturated bright pixels if you simply contrast the image to bring up those values, even though they are plenty bright relative to background.
Dr. David Knecht
91 N. Eagleville Rd.
> On May 1, 2017, at 3:49 PM, Jeremy Adler <
[hidden email]> wrote:
>
> The limitation is the human visual system - an 8 bit range is more than anyone can identify in an image displayed on a monitor.
>
> Realistically we cannot accurately discriminate 24 intensity levels on a monitor, except under highly artifical conditions - our visual system has not evolved for accurate intensity resolution: edges, objects, shapes we can manage under very uneven lighting but as a consequence we are very poor at intensities.
>
> Software can work with the whole 16 bit range but we cannot, and we are blind to much of the information present images and need tools like Brightness and Contrast and histograms.
> False colour look up tables help when intensity is the primary consideration.
>
> Jeremy Adler
> Uppsala U.
>
>
>
>
> ________________________________________
> From: ImageJ Interest Group [
[hidden email]] on behalf of Knecht, David [
[hidden email]]
> Sent: 01 May 2017 20:06
> To:
[hidden email]
> Subject: Re: 16 bit image visualization
>
> When I go in to Image/Color/edit LUT, I only get 8 bits worth of LUT to adjust even when it is a 16 bit image. Am I missing something? Dave
>
> Dr. David Knecht
> Professor , Department of Molecular and Cell Biology
> University of Connecticut
> 91 N. Eagleville Rd.
> U-3125
> Storrs, CT 06269-3125
> 860-486-2200
>
>> On Apr 28, 2017, at 5:09 AM, Jeremy Adler <
[hidden email]> wrote:
>>
>> clarification of earlier post
>>
>> Adjust brightness and contrast works with the LUT used by your image.
>>
>> You need to save your new lut (max set to zero) in the LUTs folder of ImageJ and when you restart it will appear in the list of LUTs.
>>
>> So you need to display your image in the new LUT before running brightness & constrast.
>>
>>
>>
>>
>> ________________________________________
>> From: ImageJ Interest Group [
[hidden email]] on behalf of Jeremy Adler [
[hidden email]]
>> Sent: 28 April 2017 05:51
>> To:
[hidden email]
>> Subject: Re: 16 bit image visualization
>>
>> It is very easy to set the display of intensities above the selected threshold to zero - or any other value.
>> Use Image/ Color/ Edit LUT
>> and set the display values for the maximum intensity to 0,
>> then save the LUT.
>>
>>
>> ________________________________________
>> From: ImageJ Interest Group [
[hidden email]] on behalf of Knecht, David [
[hidden email]]
>> Sent: 27 April 2017 23:14
>> To:
[hidden email]
>> Subject: 16 bit image visualization
>>
>> When we collect 16 bit images, it is sometimes because we want the dynamic range to visualize structures or cells that are of wide ranging intensities. However, as far as I know, it is difficult to isolate different intensity ranges in a 16 bit image and then play with the brightness/contrast of those pixels. What I think I am looking for is a tool like the Adjust Contrast/Brightness sliders, but be able to set values above maximum the slider value to 0. Or a tool like the Adjust Threshold tool, but instead of highlighting the pixels it would set pixels outside the selected range to black. Another way of looking at this would be the equivalent of the min and max transparency bound in a projection. I am wondering if such a tool is available in ImageJ or somewhere in the plugin universe and I have just not found it. Thanks- Dave
>>
>> Dr. David Knecht
>> Professor , Department of Molecular and Cell Biology
>> University of Connecticut
>> 91 N. Eagleville Rd.
>> U-3125
>> Storrs, CT 06269-3125
>> 860-486-2200
>>
>>
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