AUGUST Challenge - the Kodalith effect

Question

I have a suggestion for an August Challenge.

A long time ago, in silver photography, we used to buy Kodalith Ortho Lith films from Kodak.

This film had the particularity of cutting  shades of gray to black and white values, the Kodalith effect.

Kodalith film ( faq )

suggestion:

try to create a program that  open an image, and cut many shades of gray, leaving only

black or white values with a little bit of gray values , as Kodalith film did in silver process. 

beginning with a normal color image:

ending with this picture: it gives an art kind of effect:

Answer 1

Here is my version for the Kodalith effect Challenge:  program no:  VJC201

Answer 2

This is my solution: VCZ347.

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Nonki Takahashi

Answer 3

wow ! cool art graphic Nonki !

Answer 4

I noticed that there are subjects that lend themselves better to the Kodalith effect.

For that skyscrappers image, as the sky is gray day cloud flat sky, the emphasis is put on the building, and the strong perspective.

I found the final Impact is best, because there is less unnecessary distracting objects.

The processing time is around 3-4 minutes without litdev possibilities.

final program no:  KKM457

Answer 5

VCZ374 takes about 1 minute to convert.

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Nonki Takahashi

Answer 6

wow ! thanks ! super !

Answer 7

Here is a new version , but with LitDev extension in the program.

it really improve the time process to almost snapshot !!!!!

program: ZVK524