Legacy ImageMagick Discussions Archive

Sorry, I guess I missed that discussion. -connected components is also a solution for finding the black pixels from the white ones. That was also a good suggestion.


Indeed, I already use -connected components, from a script that I rewrote, using some ideas, that you previously posted. The ...

I am not suggesting you use it to preserve large areas. I was only suggesting that you use it to thin your lines to 1 pixel wide. Then use txt: format to study the spacing between the black regions. For those regions that do not fit, write over your input black pixels with white pixels.


Thanks ...

Another method is to use morphology to change white lines that are wider than the specified width to, say, red. Any remaining white will be narrow. Then change any sequence of white-then-black to white-white. Then change red back to white.


Thanks

How do I this?, I am little familiar with using ...

My code generates pretty accurate images that represent the dimensions of series of images.

However occasionally it makes a mistake...

for example the following image: where the 4th black line needs to be removed.

https://image.ibb.co/ceiPFe/example.jpg

Note: this image has been scaled ...

Thanks for those, was just wondering if there was switch as it can be a bit laborious, with long fx statements.

With the precision of the value give by of u, will i get the exact value when I do 65535*u?

Is there a simple way to use the -fx command with raw values rather than normalised, i.e. 0-1

for example

convert rose: -fx 'debug(u)' null

I would like to work with the raw 16bit value stored, or even its 8-bit equivalent, if possible.

Why not leave the legacy names as is:

and introduce lGray, sGray and lRGB

then you have Gray, RGB, sRGB as legacy values

and new values of lGray for linear Gray,
sGray for Gray using the sRGB gamma
lRGB for linear RGB

basically make it very clear what you mean with the new terms but support the ...

How many pixels wide and high?

The "-blur 0x7" will take time. Supplying a radius will reduce this, eg "-blur 21x7". Faster still, use integral images (see Windowed mean and standard deviation ), eg:
convert in.tiff -process integim -process 'deintegim w 21x21' out.tiff


some scans 3000px ...

Analysing film scans I use the values of -fx minima.r, maxima.r, minima.g, maxima.g etc.

Is there a fast (these are 50mb files or more), way of calculating these values but removing outliers, (which is noise either from the scanning process or scratches on the original)

I am currently using -blur ...

Were are you seeing 6.9.9.24 beta? I am using https://github.com/ImageMagick/ImageMagick.git

I didn't see that tag, or issue etc

Did an issue/bug reported get created for this?

Thanks fred, I will upgrade at some point. My follow up was just offered as 'way around' the 'issue' by just allocating more memory, than ideal, for grayscale images only.

I assume the default limit for memory is set at the physical limit, by increasing it to some sensible amount above the amount ...

Thanks, in which case it seems to make sense to increase the memory limit beyond the physical ram, I have 12G, and

identify -list resource shows Memory: 11.445GiB, changed them convert command too:

convert -limit 20G infile outfile

and no need to for any temporary files.

I have the following 2.3905GB grayscale file.


$ identify n10_757_a_full4800_exp1_001.tif
n10_757_a_full4800_exp1_001.tif TIFF 27360x43680 27360x43680+0+0 16-bit Grayscale Gray 2.3905GB 0.010u 0:00.000


a simple rotate 90 results seems to require 8.9G?


convert -define registry:temporary-path ...

fmw42 wrote: 2017-11-13T14:04:51-07:00 See further updates in my example above.

Thanks fred again for you assistance!