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improve image of hplc chromatogram

Posted: Tue Apr 28, 2015 2:45 pm
by jakkaas
Hello friends, i am new to the forum and so sorry if i hav posted in wrong place.
Well i had done a hplc analysis some 3 years back using agilent hplc and chemstation analysis software. I saved the result in form of pdf. I had to submit an paper on that analysis so i include the figure of the chromatogram by taking the figure from pdf and improving its resolution. Now the editor are asking for a better impage with improved resolution.
How should i do it. I hav jpg file of tge chromatogram. Which software should i use.

Thank you

Re: improve image of hplc chromatogram

Posted: Tue Apr 28, 2015 2:55 pm
by tom jupille
Unless you have access to the original data, there may not be much you can do. Once information has been thrown away (by compressing an image) it can't be recovered.

First look at the jpg file using PhotoShop or GIMP. If the image quality is adequate for your purpose, you can use that.

The resolution of the pdf will be no higher than that of the original image, so open up the pdf using Adobe Acrobat (you can probably use Libre Office as an alternative) and zoom to something like 400%. If the resolution looks OK at that scale, you can zoom back to 100%, select the area to be copied, then zoom back to 400% and then CTRL-C to copy. You can then paste that copied image into whatever LibreOffice, Word, Powerpoint, or whatever.

If the resolution is poor when you zoom the pdf, then there's nothing you can do except go back to the original data and program and generate a new chromatogram.

Re: improve image of hplc chromatogram

Posted: Tue Apr 28, 2015 3:07 pm
by jakkaas
Thank you very much for ur quick reply. I hav actually left the institution, so access to the file is impossible for me. I hav asked my friend for the original file but since its 3 year old, it would b a difficult task.
I hav tried the pdf thing which u r suggesting but the problem is the peak lines are very faint color which is causing a problem. So is there any software which can overlap line without much effort n is it ok to do it?

If in cas if i hav the original file than wht should i do. That pc is to old, so i hav to take the original file n do the processing. Which software should i use it?

Re: improve image of hplc chromatogram

Posted: Thu Apr 30, 2015 1:51 pm
by carlo.annaratone
You can use this software

http://digitizer.sourceforge.net/

which allows you to digitize back to spreadsheet format printed graphs.

Re: improve image of hplc chromatogram

Posted: Thu Apr 30, 2015 11:05 pm
by tom jupille
I hav tried the pdf thing which u r suggesting but the problem is the peak lines are very faint color which is causing a problem. So is there any software which can overlap line without much effort n is it ok to do it?
Assuming that the resolution in the pdf is adequate for you and that the only problem is the dim lines, once you have copied from the pdf, paste it in to any good image editing program (PhotoShop is the "gold standard" for this, but the freeware GIMP program will work as well). Then you can blur the image to make the lines "fatter", and then decrease the brightness and increase the contrast to make them stand out. You will have to tinker with the settings until you get something acceptable.

Here's a quick example (original on top, blur/darken/contrast on bottom):

Image

Re: improve image of hplc chromatogram

Posted: Fri May 01, 2015 2:20 am
by jakkaas
Thank you Carlo, i will look at the link.

Thank you Tom. Thats one of the things i wanted. Can you recommend me any GIMP software which i can use without much fuss as i am running out of time. Like a click would dampen the lines. Sorry if i am asking more

Re: improve image of hplc chromatogram

Posted: Fri May 01, 2015 2:18 pm
by tom jupille
GIMP is a freeware image editing program. Google it.