Option to read RGB value of specified pixel

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1x1
Posts: 6
Joined: Sat Aug 15, 2020 3:01 am

Option to read RGB value of specified pixel

Post by 1x1 »

Hello,
Im looking if NConvert can read the RGB pixel color at x y, of an jpg/png file.
Sorry if it is present somewhere, I found nothing about...
Thank you to give me the command :)
SAMSAM
Posts: 11
Joined: Sun Sep 15, 2019 5:14 pm

Re: Pixel color reading

Post by SAMSAM »

What's the practical meaning in the nconvert program?... :?:
cday
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Re: Pixel color reading

Post by cday »

1x1 wrote: Sat Aug 15, 2020 3:12 am I'm looking if NConvert can read the RGB pixel color at x y, of an jpg/png file.
No way of doing that directly using NConvert I can see, I don't know whether it might be possible using Pierre's GFL SDK about which I know nothing, but a quick internet search indicates that it should be possible using the ImageMagick command line tool, if that is any help...

Using NConvert you should be able to crop out a specified pixel, if you create a batch file specified using a simple user interface, but would then have to obtain the RGB value of the pixel using another tool, such as one the GUI programs XnView Classic or XnView MP.
1x1
Posts: 6
Joined: Sat Aug 15, 2020 3:01 am

Re: Pixel color reading

Post by 1x1 »

SAMSAM where is the useful information in your post.
Do you think that reading a pixel color have nothing to do inside an console image soft.

Thanks you cday for your true help!

I'm there to completely trow away this "junk" soft of ImageMagick that I already use to do this pixel color reading.
I say that about this soft because no way to get a true lossless jpeg to png convert with it, so without any pixel change...
NConvert have successful done this convert at my first try! and the bytes are identical to well know GUI soft.
So well done Pierre ;)
I was just looking to only use NConvert instead of a mix of soft, and IM seems very bad on the noise that it create... (and maybe little slow too)

So I suggest to add this pixel color reading basic feature inside the next version, it seems an easy job for Pierre.
And for a better challenge, that we can read many pixels color at once, to avoid the slowing down produced by each same image decompression when doing one by one pixel, and so maybe with a max possible request of for example 16 pixels x/y at once.

Very thanks Pierre for your great soft anyway :)
Last edited by 1x1 on Mon Aug 17, 2020 1:30 pm, edited 1 time in total.
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xnview
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Re: Option to read RGB value of specified pixel

Post by xnview »

sorry currently no way
Pierre.
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