Hi Peter,
I routinely use ImageJ to determine percent area of gray levels on BSE
images.
- Upload your image
2.Use the Image tab and select the type of image (e.g. 8-Bit)
3.In the tool bar on top, use the rectangle box to outline the area you
want to analyze. Drag the box over the image‹you need to do this or you
will include the scale bar etc. in your analysis of gray levels.
- Use the Image tag, go down to ADJUST, and the next menu will take you
to THRESHOLD.
- This gives you a histogram with slide bars. Just determine the range
of gray levels that represent a given phase, and drag the slider bars to
the low and high values for each phase. This will give you a read out of
percent area for a given range of gray scales. When I acquire my BSE
images, I also do a few spot EDS analyses to confirm the phase identity
for each gray level.
This is not purely automatic, as you need to manually set the sliders for
each phase. And, there is a bit of art required as you have to make
decisions about what the thresholds are for each phase. But I¹ve found
this to be a fairly rapid way to determine percent area of phases in a
given image. I have found that this image processing by gray level often
reveals fine grained distribution of a given phase that was otherwise
missed by optical observation of the images, and it also enhances some
textural features such as overgrowths and inclusions.
ImageJ has many other functions such as determining particle size
distribution in an image, determining max and min dimensions, aspect
ratio, etc. There are some online tutorials on using ImageJ but these are
pretty dense. If anyone on this listserv has documents or tutorials on
other mineralogic applications of ImageJ or other image processing
routines, I would be happy to post these to a website on the Teaching
Mineralogy website for all to use. I think there¹s a lot of power in this
type of image analysis software that could be more widely used.
Hope this info helps.
Dave Mogk
Montana State University
On 7/22/16, 4:20 AM, "pthy@ucdavis.edu" pthy@ucdavis.edu wrote:
Hope that somebody reading this message can give me a push in the right
direction.
I am looking for an image analysis program that can perform automated
modal analyses of gray-scale, or false colored, images, like BSE or X-ray
maps (TIF format). Have been directed toward ImageJ, but appear to need a
relevant plugin/macro.
If you have experiences with modal analyses of petrographic images, I
would appreciate your input.
Thanks to all,
Peter
MSA-talk mailing list
MSA-talk@minlists.org
http://lists.minlists.org/mailman/listinfo/msa-talk
Hi Peter,
I routinely use ImageJ to determine percent area of gray levels on BSE
images.
1. Upload your image
2.Use the Image tab and select the type of image (e.g. 8-Bit)
3.In the tool bar on top, use the rectangle box to outline the area you
want to analyze. Drag the box over the image‹you need to do this or you
will include the scale bar etc. in your analysis of gray levels.
4. Use the Image tag, go down to ADJUST, and the next menu will take you
to THRESHOLD.
5. This gives you a histogram with slide bars. Just determine the range
of gray levels that represent a given phase, and drag the slider bars to
the low and high values for each phase. This will give you a read out of
percent area for a given range of gray scales. When I acquire my BSE
images, I also do a few spot EDS analyses to confirm the phase identity
for each gray level.
This is not purely automatic, as you need to manually set the sliders for
each phase. And, there is a bit of art required as you have to make
decisions about what the thresholds are for each phase. But I¹ve found
this to be a fairly rapid way to determine percent area of phases in a
given image. I have found that this image processing by gray level often
reveals fine grained distribution of a given phase that was otherwise
missed by optical observation of the images, and it also enhances some
textural features such as overgrowths and inclusions.
ImageJ has many other functions such as determining particle size
distribution in an image, determining max and min dimensions, aspect
ratio, etc. There are some online tutorials on using ImageJ but these are
pretty dense. If anyone on this listserv has documents or tutorials on
other mineralogic applications of ImageJ or other image processing
routines, I would be happy to post these to a website on the Teaching
Mineralogy website for all to use. I think there¹s a lot of power in this
type of image analysis software that could be more widely used.
Hope this info helps.
Dave Mogk
Montana State University
On 7/22/16, 4:20 AM, "pthy@ucdavis.edu" <pthy@ucdavis.edu> wrote:
>Hope that somebody reading this message can give me a push in the right
>direction.
>
>I am looking for an image analysis program that can perform automated
>modal analyses of gray-scale, or false colored, images, like BSE or X-ray
>maps (TIF format). Have been directed toward ImageJ, but appear to need a
>relevant plugin/macro.
>
>If you have experiences with modal analyses of petrographic images, I
>would appreciate your input.
>
>Thanks to all,
>Peter
>
>
>_______________________________________________
>MSA-talk mailing list
>MSA-talk@minlists.org
>http://lists.minlists.org/mailman/listinfo/msa-talk
>
