Command Line Interface ~ Linux

I never knew it was "punk" to use a Command Line Interface, but it appears to be so. 

Once the idea struck, it became clear that, yes, indeed, I am increasingly anti-GAFAM (Google Amazon Facebook Apple Microsoft).  OK, so this blog is hosted on one of the GAFAM systems, but this can rectified at a time of my choosing.  Cell phone?  Yes, that too can change.  The tablet can change.  The Big Computer was for a very short period of time running a techno-tyrannical operating system, but most of the time for the past 30 years has been liberated.  It's a matter of effort.

Once I understood a little better the history of punk I could re-frame, re-context the contents of the prior paragraph.  Punk started as a youth movement that responded to arrogant "elite" class Thatcher-ism in the UK.  The US version of punk was something a little different.  It dealt with right wing politics and capitalism.  In both cases punk was a reaction to Bad Things perpetrated by "elite" powers far removed from the experiences of everyday people.  

GAFAM power is even greater than what the original punks responded to starting in the 1970's.  Techno-tyranny is extra-political and trans-national.  It determines what exists and what does not, what is remembered and what is not, what is acceptable and what is not, and it imposes a value system easily consumed by the masses.  Significant portions of the system is "free."  Whatsapp, Facebook, Blogger (the site I write this on), Gmail, Yahoo mail, Twitter (yes, I know it's newer name), Amazon, FaceTime, iTunes, etc, etc, etc on the surface and at first blush cost nothing.

The "costs" are carefully hidden from users.  Many (most?) "free services" on the internet are synonymous with loss of privacy, intrusive data collection, buying/selling of data, leading to a state of shockingly efficient, nearly seamless techo-tyranny means these services are anything but free.  Ads tailored just for our eyes are the least of it. We so quickly accept this as "the way things are" that we become numb to this truth.  Of course none of this is for our liberation, rather for our compliance and sheep-like acceptance.

I'm reminded of the early days of what later evolved into the internet.  We dug for information and knowledge using Gopher.  We spoke rather freely with each other via (unscanned for advertising opportunities) email (hosted on small systems), held community conversations on (largely troll-free) discussion forums and bulletin boards (both commonly hosted on small systems), and read news on something called Usenet.

It felt more like we were moving into a future of our shared creation, rather than a narrowly offered present imposed on us.  Freedom and liberty vs corporate tended bubbles of narrowed for our "protection" tailored for our unique, personalized, and therefore oh so special experience.  Such sadness to see things so incredibly controlled these days.

My effort to limit/restrict the influence of GAFAM now includes a review of tools used in photography.  Cameras and lenses are owned outright (this is the easy part, rather like a current day holdover of an earlier, simpler time).  My image processing tools are never rented and come from the Open Source Community (which, BTW, often implements industry standards _better_ than RentWare).  To speed the image processing pipeline up even further I sometimes use the Command Line Interface to invoke tools that do specific jobs quickly and efficiently.   I must, by definition, be punk.  Huh.  Never knew.  Doesn't change a thing, actually.

Here is my evolving kept for memory reasons list of commands, expanding to include the above motivations for their being in my life.

------------------ original post ------------------- 

Notes to self:  A few useful image processing commands for running in Linux.  All these are much faster to run from the CLI than using an app that's having to manage graphics at the same time. -

convert *.jpg -average <averaged-filename>.jpg – averaging command

convert *.jpg -evaluate-sequence median <output file-name>.jpg  - a different averaging command

mogrify -resize 1920 *.jpg – resizing command

mogrify -bordercolor black -border 10x10 *.jpg – adding a thin black edge to images

mogrify -bordercolor white -border 400x400 *.jpg – adding a white border to images

convert <filename>.<file-extension> -colorspace gray <output filename>.<file-extension> – command to convert a single image to black and white

for i in *.jpg; do convert "$i" -colorspace Gray  "BW_$i"; done – Bash script to convert a bunch of files into black and white

exiftool -a -u -s -G1 <file_name> - to read EXIF image file data

gmic -input <filename.file-extension> scale_dcci2x , cut 0,255 round output <theOutputFileName>.tif - command to perform a DCCI2x upsize

LibreOffice : Impress
menu Insert | Media | Photo Album :: Slide Layout 

 

Black and White digital filters in image processing...

I'm working up to a critique that I'll post at some point in the (hopefully) not too distant future.  To get there from here I want to cover Black and White digital filters in image processing.

The topic arose in my mind when musing over a digital recipe/filter that would accurately/correctly match the spectral response curve of early silver nitrate light sensitive materials, including but certainly not limited to wet-plate collodion.

I found a digital filter that I'm very happy with and for the sake of brevity I'll dispense with the steps I took to the final form.  If anyone wants the complete details, ask.

Here's the starting image.  Top and bottom are grayscale step wedges that I developed for the Digital Zone System I've worked on.  The center of the image is a simple color chip chart.   Examples were processed using RawTherapee.

Starting point -

 

Simple color desaturation - 

Relative RGB channel mix -

Luminance human perception modeling - 

Relative RGB channel mix "Ortho" filter -

Silver Nitrate relative RGB channel mix Red=0 Green=10 Blue=90 filter - 

Comments -

Short answer:  

Digital filters for Black and White color conversions seem to do what they're supposed to.

Long answer:  

Simple désaturation sucks. Colors don't translate to the tonality my eyes would expect to see.  Yet this is EXACTLY what old Black and White film does.  Sure, the ends of the color spectrum might be clipped differently on each end.  The meat of the curve behaves just like this simple de-sat.

Relative RGB channel mix is a minor improvement over simple désaturation. This is to be expected since all channels are set to 33 percent.

Luminance human perception modeling gives an accurate translation of colors into Black and White for the way I "see" tonality and luminance.   This is an outstanding foundation from which to build tonal separation in digital Black and White photography.  Further, in-camera Sony, Fuji GFX, and Panasonic Lumix S (the only system I've looked at) all appear to conform to luminance human perception modeling Black and White jpg generation.

Relative RGB channel mix with RawTherapee's "Ortho" filter seems to look very much like modern orthochromatique film response.  If I want early silver nitrate light sensitive material response, this is most definitely not what I'd look for.  Close-ish.  No cigar.

Silver Nitrate relative RGB channel set specifically to Red=0 Green=10 Blue=90 appears to hit the target.  The tonal response curve closely matches that of old silver nitrate light sensitive materials.  Goal!

A little more:

I could spend far too long looking/comparing/evaluating various combinations of channel mixture and digital filters and this and that.  Should I ever find myself in such a state I processed a number of images.  The collection of the Madness is found here, and scroll right.

In practice, I find the luminance formula in RawTherapee to be excellent for general Black and White conversions.  To explore the early pre-panchromatic Black and White photography "look" my little "Silver Nitrate" formula gives me pleasing results.

Processing an Image

Just for fun I thought I'd post a quick comment on how I processed an image I took at Rodin's Atelier in Meudon.

Image -

... and here's what I did to it: 

• Let the in-camera meter do its best
• Ricoh 55mm wide open at f/2.2  
• *click* the shutter 
• Opened RAW image in RawTherapee
• Applied my 0EV Digital Zone System curve
• Adjusted the ends of the curves for pure white and pure black
• Opened the image in the Gimp
• Back in RawTherapee, processed the sky for tonality and contrast
• Opened the sky processed image in the Gimp as a layer over the first image
• Gimp selected the sky of the first image
• Added a black mask to the second layered image
• Filled the selection area in the mask with pure white
• Adjusted the mask "sharpness" to Gauss soften with a 10 pixel radius
• Flattened the image and saved

Done.  That's it.  That's all it took to get these the way I wanted.

The trick, of course, was protecting the whites/highlights, then applying a correct Zone 3 thru 7 1EV step curve, and stripping in the sky.