ImageJ Tutorial - Measuring Lengths and Angles
ฝัง
- เผยแพร่เมื่อ 22 เม.ย. 2014
- Use this tutorial to help figure out how to measure hypocotyl lengths, root lengths, angles of hypocotyl/root curvature, etc. Once the measurements have been made, the results from the 'results window' can be directly copied to Excel or your spreadsheet software of choice.
![[TH] VCT Masters Shanghai Swiss Stage DAY 5 // FPX vs TH | FUT vs LEV](http://i.ytimg.com/vi/r61uDZTmu44/mqdefault.jpg)
I watch countless of long videos of intro to measuring for imageJ and not one mention how to access the free hand tool. That is exactly what I needed. Thank you so much for the nice short video.
thnx for angle measurement tutorial! that;s what I wanted to know! thnx alot
Thanks for sharing the video!..awesome software!
Thank you for the video. I need to perform cephalometric analysis on a bunch of facial x-rays for which I have to mark two independent lines and check the angle between them.Can you help me in this regard? Thanks in advance!
Hi Richard,
thanks for the video.
I have 900 hypocotyls to measure (10 in each foto).
Is there any way I can do it automatically with image J ?
Do you know how to make the angle tool 360 degrees or negative and positive values of 180 rather than both sides being positive 180 degrees?
Thanks.
Hi richard, can I have a fixed reference so that i can measure all angles in reference to it, say angles with respect to vertical direction
Thanks for the tutorial. Please advise how to measure a radius.
thanks for that angle measurement trick...i was googling for tricks in msoffice and ppt for a while
Nice tutorial video, it's very informative. I have a question if you don't mind. Is there a functionality or option in ImageJ that allows the user to count the number of pixels of a particular color and/or get its percentage from the total number of pixels?
For example, I have an image with color A and B, I want to get the total number of pixels of color A, or color B. (For simplicity, we can let color A = black, and color B = white)
I would really appreciate if you could respond to my queries, it will be a great help. Thanks in advance.
Jar,
Yes, you can use the color threshold option to segment out the colors you are interested in. Then you can use the particle counter to count the areas of the individual particles/pixels.
Hi
I have a question when you set the scale that means setting the pixel number corresponding to some length which you draw on x-axis, but i was wondering that the image resolution in pixels is not the same as it can be seen in the video. I think it will give us wrong length values in y direction.
Please let me know if i am wrong or i have misconception about it.
Hi Shozab,
If you have a ruler, or some other feature, in your picture you can use that to set the scale. For example, I was using the ruler at the bottom of the image to set the scale to. Hope this helps!
Hi Richard your video is very good, but I have a question. If you have several roots in a picture. Can you automate the analisys?. I mean can I create a mask in B&W and measure all length of roots? I have a complete radical system of maize and I would like to mesure his full length. Do you understand me.
Thanks for the video and sorry for my bad english
Regards
+Carlos Torres Hi Carlos,
I think you probably could automate the analysis in ImageJ, but you would have to write some sort of script and that is beyond what I know how to do. For automation I suggest you try the program RootNav (www.plant-image-analysis.org/software/rootnav); it can automatically measure several characteristics of your roots (length, tortuosity, skewing, etc.), so that may be your best bet. We have a scientist down the hallway who writes programs in MatLab that are a little more stringent, but RootNav is hopefully good enough to extract some phenotypic data. There is another program called RootGraph (www.plant-image-analysis.org/software/rootgraph) that you could try out. Good luck!
-Richard
Hi Richard, your video really helped me, but I have one question - the size of angle is in rad or degrees? I could not find it anywhere...
Thanks for your answer :)
I believe the default for the angle settings is degrees.
hie Richard, very insightful video. I have a question though. How do i set a scale for any random image?, like for me i have images from an optical microscope with (5, 20, 50 & 100x) magnifications
Hi Tatenda,
Are you obtaining images through a camera set up that is attached to the optical scope? Usually, there is software used to obtain the images and within the software you should be able to add a scale bar to the images and then set the scale as I described. If not, then you need to have some way to calibrate the scale by knowing the size of an object within the image or by imaging an optical micrometer (imagej.net/SpatialCalibration) prior to obtaining the image. If the zoom is changed you will also need to take this into account.
Thank you so much Richard, i managed to fix the calibration issue.
What is the mean given in the results?
Hi Richard,
I have to measure capillary tube length in one of my angiogenesis experiment. Can you help me with that using Image J? Its so confusing to me now.
Hi Umar,
If you can send me an example image (hilleary@wisc.edu), I can make a similar video for you. Be sure that any images have a scale bar in order to set the proper scale for length measurements.
thanks
Dear Richard,
Thank you for your useful video. It really helps me.
I'm working on lettuce seedlings in agar medium and I have some questions. Would you please help me ..
1. Lettuce root can not grow properly in agar. Their roots become brown after 3-4 days and they stop (attached picture) . I've tried several kinds of agar in different concentration and pH, but there was no improvement. Whereas in petri dish on paper the seedlings have suitable growth, and even on the surface of the agar, but not within it! What should I do? Can washing the agar help? What is your plant in this video and what is your medium?
2. For evaluating the geotheropism of roots, would you please give me the protocol?
Thanks in advance
Hi Somayeh,
Apologies for the belated reply. The plants in this video are Arabidopsis thaliana and they are grown on 1/2 MS salts media (0.5% phytagel, 10mM sucrose).
How would you find an error in length from this? (In terms of pixels to mm I think).
+Josh Mulkeen
Hi Josh! Could you clarify what you mean by error?
hi Richard
i want to know ho to measure the stem anatomy by image j in micrometers...send me step plzz
these is very useful video
Hi Richard,
This is very good video .
Do you have your another videos ?
can i use video and get what is change in previous image and next image , so that i can know that what is change in length.
i am engineering student .
Thank you.
ridhi vora Yes, you can do measurements between multiple images. Just be sure to make the scale similar between images.
Hi Richard ,
Thank you so much for your kind reply,
I have one question to ask you..
I have multiple images with me , say 150.
now i have picture with me .
i have marked 3mm lines on that .
now as i am increasing number of image, my lines are going away from each other .
i want to find out how much they are going away .
can i send you one video or no of images ?
Thank you,
looking forward to your reply .
Regards
Ridhi
ridhi vora Sure, you can send me a video. Shoot me a private message and I'll give you my email address.
ridhi vora Sure, you can send me a video. Shoot me a private message and I'll give you my email address.
how should i give you private msg ?
should always use the longest length ref possible ie use 8 instead for 8 times less error
Hallo Richard, thank you very much for this very informative video. i have Aquestion please, how can i measure the Angle between tow line without any contact , for example 2 semiparallel lines? can you help me please
Abdullah Al Maktary could you provide me with the image?
yes , where can i upload this image?
img.medscapestatic.com/de/pi/artikel/4900674/fig17.jpg
i could not uplaod my image hier, bit this example from internet , how can i measure the angle between one wire in one bone and the other wire in the other bone ?
i do a clinical study like this in this image