Posted by
Charles Davis on
Jun 14, 2016; 8:15pm
URL: http://imagej.273.s1.nabble.com/Help-tp5016640p5016649.html
Michael, I had figured out that I needed to convert to grayscale. Otherwise
I assumed I would get RGB values. I also dug deeply enough to have found the
choice of grey conversion. As I'm not doing perceptual analysis, I kept the
non-weighted conversion.
The answer was to simply File>Save As>Text Image. DUH!
I am comparing two images that are very similar. I have been subtracting
them w/ Photoshop, but have also found that imagej can do that subtraction.
:-)
I am wanting to count pixel values and use a custom algorithm to quantify
the difference. I probably could use imagej, but the learning curve is very
steep and I am comfortable w/ Excel.
Thanks...
-----Original Message-----
From: ImageJ Interest Group [mailto:
[hidden email]] On Behalf Of
Michael Schmid
Sent: Tuesday, June 14, 2016 1:52 PM
To:
[hidden email]
Subject: Re: Help?
Hi Charles,
it seems you need a grayscale image first. Assuming you are starting
with RGB, use Image>Type>8 bits.
Make sure you have the correct choice of "Weighted RGB Conversions" in
Edit>Options>Conversions
https://imagej.nih.gov/ij/docs/guide/146-27.html#toc-Subsubsection-27.13.11Then save as text image.
Anyhow, what kind of analysis with all pixels do you want to do in Excel?
I guess that ImageJ could do essentially everything that can be done in
Excel, but much faster.
Michael
________________________________________________________________
On 2016-06-14 18:10, Charles Davis wrote:
> I'm a new imagej user and am having a problem. I know that imagej will
> generate the data that I want, because I [somehow] got it to do it once.
But
> I don't remember the sequence of operations that I went through to get
that
> result. I have spent 2 weeks, working several hours each day and have not
> been able to study and find the answer or try everything that seems
> reasonable. My pride and ego is at ZERO! I can't do this w/o help.
>
>
>
> Background:
>
>
>
> I'm using a Nikon D810 camera which produces large files. I need a .csv or
> .txt file w/ the brightness values. I don't want a Histogram, but the data
> behind the Histogram.
>
>
>
> I have been able to produce files w/ all the pixel data [X, Y, R, G, B] in
> one row. That is too large to load into Excel [36,200,000 is too many
rows].
> Yes, I have successfully attempted to break it up into several smaller
> files, but that takes hours to do one file! Then I have to extract the
> summary data from each of these 2-dozen+ files and create a global summary
> file.
>
>
>
> As I said, I was able to [somehow] create a .txt file that was organized
> differently. I had all the Y's in the rows and all the X's in the columns.
> The data in each cell was the gray value [I think]. This had only 4913
rows
> x 7359 columns and loaded into Excel [slowly]; it's still big, but
> manageable.
>
>
>
> Sorry for the long intro, getting to my question: How do I recreate
another
> of those Measurements.txt files, w/ only gray brightness data in cells and
> in a 2D array?
>
>
>
> TIA!
>
>
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