I have been using Microsoft paint to calculate the average size of nanoparticles. But, I don't think its relevant. So, If anyone working on the determination of the size of nano-crystal, please share your method how you calculate the size.
I agree with the other participants the ImageJ free software is an excellent program for image processing .
With this program you can process an image of any type, from electron microscopy or any other images from different microscopic instruments.
Just to complement previous answers a short comment :
When you want to perform actions on an image ( TEM, SEM) etc. , using a image processing program is necessary before " calibrate the image." This is because the software does not know with which magnification the image was obtained and therefore does not have a valid reference that allows to accurately measure the objects in the image.
Although your TEM image probably has a scale bar, but unfortunately the ImageJ program can not interpret the scale bar. You can only make measurements in pixels, but have no meaning in terms of distances.
To perform the measurements, you must first calibrate the image, that means, manually stablish the image scale using something on the image with a well known size or distance, for example the scale bar that usually appears at the bottom of the image ( either left or right ) is suitable for the purpose.
Through the following link , there is an short and clear explanation of how to adjust the scale value in the software ImageJ :
ImageJ is a free software that has some auto counting/sizing options, and you can use it to measure particles manually too. http://rsbweb.nih.gov/ij/download.html
It gives x value, y value and the total value. Is this value talking about the pixels? If so, I then have to use formula. I used to use a formula given below for the paint software.
Particle size = pixels of particle x length of scale/pixels of scale.
you can set the scale before doing measurements, some TEM/SEM image files have the scale inbedded
select analyze and set scale, and just type the scale in. There's quite a lot it can do, you will just have to play with it to see what else you can get it to do. Good luck.
I agree with the other participants the ImageJ free software is an excellent program for image processing .
With this program you can process an image of any type, from electron microscopy or any other images from different microscopic instruments.
Just to complement previous answers a short comment :
When you want to perform actions on an image ( TEM, SEM) etc. , using a image processing program is necessary before " calibrate the image." This is because the software does not know with which magnification the image was obtained and therefore does not have a valid reference that allows to accurately measure the objects in the image.
Although your TEM image probably has a scale bar, but unfortunately the ImageJ program can not interpret the scale bar. You can only make measurements in pixels, but have no meaning in terms of distances.
To perform the measurements, you must first calibrate the image, that means, manually stablish the image scale using something on the image with a well known size or distance, for example the scale bar that usually appears at the bottom of the image ( either left or right ) is suitable for the purpose.
Through the following link , there is an short and clear explanation of how to adjust the scale value in the software ImageJ :
The question is: TEM image is 2D representation od 3D structure, so how You know what You will measure - projection of 'nano-plates' existing in the structure with unknown orientation? ImageJ is not bad, set the scale and measure all You want, but Im not sure if TEM software (the same which was used for obtaining images) could be beter.
ImageJ is really good for image analysis for estimating size of nanoparticles from micrographs. Just setting the global scale one can measure and obtain size distributions.However, Since what we see in TEM image is 2D projection of 3D structures, there will be error in size estimation / shape (aspect ratio) esimation by ImageJ particularly if there are randomly oriented structures. I agree with Janusz.
@Janusz, TEM imaging is the fastest method to measure NPs size. The main reason is that usually you are able to have them well separated on the grid, therefore easier to process. If you use SEM or AFM usually you have a nice agglomerate of particles from which you can't get much information.
2) check if the particles remain after 15 minutes on the bottom, if so, point 1 if its ok go to point 3
3) mica immersion in the solution for a while and leave to evaporate
4) put mica under AFM tip
I think I measure all materials with AFM and if there was some trouble with 3D representation of structure/particles I made sharper tip using FIB. If there was some particles differ than other (for instance polymer with silver) cantilever was modified to obtain better PhaseImaging contrast on higher frequency. Of course - according to topic - all afm systems are metrology tools, so with afm one can measure all dimmension of particles in 3D.
yeah yeah sure you can. But if you have a look to a lot of publication around most of the afm picture of nanoparticles have low quality. No doubt you can use it, I just think that for the purpose of measuring particles size TEM is faster...
Yes , I agree that Image J is very good software to analyze tool of TEM images. which is freeware . In this you can set scale as available in the TEM image.
I was unable to set threshold for the picture(TEM image). The circular black spots the nano particles and I have to determine the size of these particles. When I set threshold and analyze particles, Image J splits up these spots into a large number of dots and analyses. This may affect the particle size. This does not give actual particle size. My TEM image has large no. of nano particles many of which are overlapped. I find Image J useful for the images with less noise and seperate particles. Do somebody help me how to set threshold limit for the TEM images??? I was unable to upload the image here.
Is a good idea to upload the image, as we can see the difficulties and details of your image.
Please, below the add answer dialog, there is the option "add attachment", Select the option "file", search your filewhere is loacated on your PC and press "Add".
Last time I tried in the same way but was unable to upload. Now, Its done. Thank you Carmen Serra for your help. I hope you will be able to resolve my problems.
Once I saw the TEM image , I agree the particles are indeed very close together, and therefore it is not easy for any program to identify and count the particles separately.
Of course I recommend you to try to get clearer images with more separate particles, as it is very difficult to correctly analyze the particles and obtain good results. That means, better sample preparation, to obtain more clear and clean images.
The most important thing is to have a good image, that offers you guarantees to process it, otherwise you'll always challenged to identify the particles.
I sent a separated document with some results after some image processing.
You can try with a more diluted nanoparticles suspension so it will not be as dense. Unfortunately, nanoparticles on a TEM grid often tend to agglomerate (especially polymers) and it can be difficult to do it automatically. Maybe you will have to do it by hand on at least 200 nanoparticles. Of course you have to be careful selecting nanoparticles of every sizes to be as representative as possible.
You should try remaking your sample. I would recommend a more diluted sample and also sonicate the sample to help limit agglomeration. Also the sample should be prepared right before you take your images to help reduce the agglomeration as well.
Thank you Marc-Antoine and Mohamed for your suggestion. I have been counting particles manually and I am trying to include almost all the possible sizes from the images.
Image J works well as stated above. Another improvement that can be made: Cryo-EM will allow for more accurate sizing of non-dried, non-deformed nanoparticles.
Try digital micrograph, which is the best software. You can calibrate it easily for low resolution images. You can find unregistered version in google that will be enough for you.
Try with a Standards nanoparticles that can you using to doping the sample. The sizes is known with very exactly and are spherical mono disperses. Using a free software such as Scion Images you can calibrate the pixels to nm.
I do also agree with the other colleagues. The ImageJ (free) software is an excellent software for image processing. Please take into account what Carmen Rodriguez said about the calibration using the micrographs' scales.
There are a lot of softwares which have already been mentioned here. You can try with Gatan DigitalMicrographs which make me more comfortable to handle.
The size by TEM images can be calculated by image processing software. u can use as the other participants said imageJ software. its free and easy to use
As the others pointed out the best way is to use the Gatan software, it is easy and you can get the size of the particle in seconds. The second way is the use of the ImageJ software,that you can calibrate the imageJ in nm and so you can get the particle size in nm directly instead of getting it in pixels. Good luck
Usually the software comes with the option of scale bar. If not then I think best way is to use the copper grid (the manufacturer always specifies the grid wide) images at various magnification. Those images can be taken as standard for all images for that specific TEM instrument.
Whatever software you use for analysis (DM3, ImageJ, Semper...) the main point is that you need to be wary of artefacts, which can be due to one of 3 classes:
a) overlap of particles if the density on the support film is too high (problem of particle separation in 2D projection),
b) choice of the optimum threshold if you use an automatic particle measurement software package (problem of thresholding) and
c) the sensitivity of the technique itself: HREM lattice imaging has very high resolution but low sensitivity for particle diameters
If you use the scale bar to "calibrate" ImageJ or another image processing program,and you want accurate and perhaps traceable results, be sure that the scale bar itself (i.e., the scope) has been calibrated at the magnifcation levels you wish to use. By this I mean that a traceable artifact (available from EM supply vendors like Pella) should be used to obtain absolute calibration of the magnification. Then the correct calibration factor can be entered into ImageJ. Relying on the nominal magnifcation/scale bars of the scope may result in bias/error for which you will not be aware.
If u need Just I am sujjested to u Small Angle X-ray Scattering good for average size of particle for whole sample. The Scattering curve gives the average size of the particle for whole sapmle.
To Kali, Small Angle X-ray Scattering may only be accurate for spherical particles. For other type of particles it is not very accurate, Simply it designed to handle the spherical particles. However, the new versions of the X-ray instruments, for example the 2013 version it can handle non-spherical particles. In conclusion I do not think that Small Angle X-ray Scattering is the proper way.
To Atul in fact you do not need any additional software. In ImageJ you can setup the scale in any units you need. You do not have to convert from pixel to mm or nm. Here how you can do this "Draw a line between two points of known distance such as a ruler on the photograph. Go to Analyze → Set Scale. In the Set Scale window the length of the line, in pixels, will be displayed. Type the known distance and units of measure in the appropriate boxes and click OK. Measurements will now be shown using these settings."
For particles that are close together, it is indeed very difficult detecting and correctly analysing the particles to obtain good results as mentioned by Carmen. That is why for similar pictures that I analyse, I detect the particles on a watershed image and measure them on the Euclidean distance map. This allows measuring the maximal inner circle diameter of the particles. Eventhough I used iTEM, the approach is generic enough to work with ImageJ. For near spherical particles the results are similar to manual measurements.
The best option for you is Image J, which is a free software and it can be used to measure the size of particles. You must use the pluggins PSAdev or PSAr 12 Macro to count and measure nanoparticles with a previous calibration of the micrographies by using the option set scale
I confirm, I am using ImageJ almost since this program exist to treat TEM images.
The main concern willbe to set th good scale in ImageJ.
Sometime the file format ofhe TEM picture isdirectly reconized by ImageJand the scale is set automatically. This is the case for .dmg files recorded using Gaten Software. You can dl an ImageJ plugin that willread the .dmg file.
Once the scale is set you just have to measure the particle or object with the "straight line" tool for exaple and push "M" on your keyborad whe done. This will open the measument window and record the measurment you just did. you can repe this as much as you want and thus collect a lot of data that can be use to get a size distribution for example.
Image J software is good for you, but i think you can measure the size distribution by detection the same samples using ZetaSizer or other machines. That will give you a better result.
The only problem with zetasizer is that you don't measure the same diameter. You measure a diameter deduced from the electrophoretic mobiliy of a population of particles, this is not the same quantity that you measure with SEM or TEM.
Another detail, if images are saved in tiff file, you can usually find the pixel size in the file header, it is better to resize the image using this information instead of approximative method using the scalebar
Hi, You can use JMicrovision software to count and measure mannually the nanoparticle size and then process the data by other prof curve-software like Originlab or sigmaplot. Hope that helps you.
the size of nano-particles can be calculated easily if you deposit your NPS on substrate at which your nps has good adhesion with the mono-layer. the thickness of your mono-layer will be the diameter of your nano particles.