Data extraction from image

[sukhiray]

How to get the data of a row drawn using cursor from an .jpg picture and plot it into a graph display?

I have a .jpg picture saved on computer. Now from that picture I need to extract data of a particular row which can be chose from the display only. Then I have to plot that extract data in graph display so that I can do analysis as per requirement, e.g. Get the peaks or valleys.

How to get the data of chosen row from .jpg picture and display it?

[dan_u]

You can use Read JPEG File to get the jpg data, then use Unflatten Pixmap to convert the data into a 2D array.

Then it's easy to extract a row, it's just indexing the array data.

Hope this helps,

Daniel

[sukhiray]

thank you dan_u.

i have tried following you advice. but there is a problem in reading file . error at read jpeg file is "LabVIEW:  An input parameter is invalid. For example if the input is a path, the path might contain a character not allowed by the OS such as ? or @.
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NI-488:  Command requires GPIB Controller to be Controller-In-Charge.". the file required to read is attached  here. 

[Dennis_Knutson]

You did not attach a file and the problem is how YOU specified the path and file and you should have attached your VI.

[sukhiray]

opss! i am extremly sorry. I attached that here..

[dan_u]

So you want to extract one of the curves in the jpg file? Good luck with that...

You should try to get the raw data instead of just a jpg.

[Weiyuan]

Well, my suggestion is: build an event structure, add mouse-hold event, save the mouse locations to an array or file.  You have to trace every curve in your image.  It is gonna be an interesting program.

[dan_u]

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Weiyuan wrote:
Well, my suggestion is: build an event structure, add mouse-hold event, save the mouse locations to an array or file.  You have to trace every curve in your image.  It is gonna be an interesting program.

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It will still be difficult to calibrate the data.... Howdo you translate the x,y mouse coordinates to physical units?

Not to talk about accuracy...

[sukhiray]

i am not going to trace each graph visible there. I need data of a particular row, say for example, the data of co-ordinate y=5. is it possible to draw a line on the graph and save the data lies on the line?

[Weiyuan]

Can you attach your labview code here, the one you said has errors.  If you just have one image, you can try ImageJ, it is free.  Draw a line and goto analyze->plot profile.