Extracting mean and standard deviation value from image

Comments and discussions about 8bf plugins which can be use in various applications like Photoshop, Paint Shop Pro or Photo-Paint
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Kanni
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Extracting mean and standard deviation value from image

Post by Kanni »

Sorry, I am very very new to it. But I know I can extract pixel data using plug-in.

Can enlighten me on ways to do it? :cry:

What I have/know now:
- Filter factory- but i think extraction of pixel data cannot be done.
- SDK (pending for approval to download- within 4days)
Do i need to have C++ programme to do it? Or the SDK is self-sufficient?

I have a sample in 8BF. How can I modify this 8BF to suit my need? Many Many thanks :wink:
I luv grain.

Ilya Razmanov
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Post by Ilya Razmanov »

http://www.filtermeister.com/ may be good choice for you - I once used it to extract some info from images into a text file (well, actually I used it more than once).

Another option may be converting image into text-based format like PGM or PPM, then opening text with some data processing software. However, I personally never tried that.

Kanni
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Posts: 4
Joined: Thu Jul 13, 2006 7:01 am
Location: Singapore

Post by Kanni »

Ilya Razmanov wrote:http://www.filtermeister.com/ may be good choice for you - I once used it to extract some info from images into a text file (well, actually I used it more than once).

Another option may be converting image into text-based format like PGM or PPM, then opening text with some data processing software. However, I personally never tried that.
Thank you for the informative reply. I have downloaded. Not yet read through the manual, but u have some code for me as reference?

If i would like to EXPORT it to my excel file, do filter meister has this function? Many many thanks
I luv grain.

ddyer
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pixel data

Post by ddyer »

Andromeda measure filter can collect pixel data over specified
paths or areas, and export data to files. Not mean and SD, but
the raw data you could derive them from.
http://www.andromeda.com/main/measurement.php
plugin developer for http://www.andromeda.com

Ilya Razmanov
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Post by Ilya Razmanov »

Kanni wrote:Thank you for the informative reply. I have downloaded. Not yet read through the manual, but u have some code for me as reference?

If i would like to EXPORT it to my excel file, do filter meister has this function? Many many thanks
Hm, I feel sure I wrote the reply to it, but now I don't see it. Ok, once again but briefly:

One of the provided PDF files contain an example of Wern's code for turning the image into PostScript ASCII mosaic. Omit the PostScript stuff and see how the filter encodes the colors of pixels as text output. That should be enough to get you started - just modify it to your needs. Also, some other examples included show how to write some stuff as text files, just make them write pixel info as, say, comma delimited values. Then you'll be able to import resulting CSV file into Excel.
Ilya Razmanov
http://photoshop.msk.ru/ - Photoshop plug-in filters

Kanni
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Location: Singapore

luminance value? ISO or photoshop

Post by Kanni »

edited for ease of reading :oops:
I am in the process of writing now. But I can't get the luminance value tally... output value often off by 0.01..(mean and std dev)

currently, formula used:
luminance =0.3* src(x,y,0) + 0.59* src(x,y,1) + 0.11* src(x,y,2)

Is my formula not accurate enough? Anyone know what is the highlighted value used in Photoshop?

ISO formula:
luminance = 0.2126* src(x,y,0) + 0.7152* src(x,y,1) + 0.0722* src(x,y,2)

Shall I use ISO formula instead? I am trying to calculate optical density value for the digital output of a Stouffer chart.
I luv grain.

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