Halftone Image From Greyscale Image Tutorial

I think this might be scriptable if anybody wants to try to do it.

1. Start off with a greyscale image. If you have a color image then do a [Color] [Desaturate] on it first. And then create another layer above it that is all black canvas area. And change the layer mode to Dodge.



2. On the black dodge layer run the [Filter} [Render] [Patterns] [Grid] filter on it. In the grid dialog choose a width for Horizontal and verticle lines of 1 to 4 or so. Choose the spacing between the lines at perhaps 10 to 20. And make the color of the lines white, and click OK.



Now Gausian blur the dodge layer to kind of round off the squares, followed by a [Color] [Auto] [Stretch Contrast] to force the colors to stretch from full black to full white.




4. Then do a [Layer] [New From Visible] and run the [Color] [Threshold] filter on it by moving the slider to the right.



Since this is all being done manually it gives a lot of room for adjustment. You can try to invert one of the layers. You can also use a filter like [Distorts] [Curve Bend] or [iWarp]. Curves can also be used on the layers to make things thicker or thinner in the results. You can also try this with other settings inside of the [Grid] dialog box. You can use the [Grid] ddialog to create only verticle or only horizontal lines etc.

Pegleg

awesome technique , peggsy !
you always bring interesting stuff from an alternative Gimp universe - i love that !

i applied G'MIC -> Recursive Median (Radius 6) on the New From Visible
and then used colour curves, instead of the Threshold because i felt the shapes were kind of ugly

Yes my thoughts are from an alternative universe but I offer them up with free gimp love. And since they are free, you can't hold me responsible if your computer locks up.

Here's another thing you can do with this technique. You can make square halftones.

What I did to get this image below is I kept the line widths in the grid dialog at 1, and instead of blurring the dodge layer I selected the white with fuzzy selection and did a [Select] [Border] of 8 (Half the spacing from the grid dialog) with Feather Boarder checked and filled the selection on the dodge layer with white. Then after streatching contrast the halftone has squares instead of dots.


Interesting effects could be achieved if you were to use the iwarp on the dodge layer before layer from visible and Threashold.



I set the results layer to darken only after creating it.

OK here's the last one for the day.

I was able to get perfect pixel squares with the help of the Height Bevel Script that soulgoode made for me a while back.



What I did is took the dodge layer and used the grid on it with the width set for 7 and the spacing set at 8. This gave me little black dots that are actually shades of grey from the image below it. Then I did a layer from visible and ran the Height Bevel Script on it with a setting of 4. What that did is put a bevel around each dot according to the greyscale value. And when you do a threashold on the resulting image you get varying sizes of black dots.

Here's the code that soulgoode made for the Height Bevel Script:


Pegleg

Sure is a beautiful horse no matter how many dots it has.

I agree

I know this is 3 years old but it's awesome! Thanks so much!

Steps in number post #1 has been turned into a script here
-> PegLeg Halftone Script for GIMP

Nice Tran!

Tran,

Thanks for the heads up. I made a couple the 'hard way' and love them so a script is the cherry on top of the sundae. The code in PegLeg's tut has been very helpful.

Dear PegLeg44,
I just saw your nice tutorial. It is 5 years old but I am just 5 days old in this group.
I copied the horse picture from your tutorial and went through all the steps but the result I got was not
like yours. It was just passable. Only thing I changed was the size because I cropped the picture of the horse and sued it in my attempt. I will be happy and thankful for any advice.
And two: I saw the script you so kindly included in the tutorial. . I copied the text and pasted it in Notepad.
How do iI make it a 'scm' file.
Thank you.
-Eureka

Thanks to the Steps creator PegLeg44 and Plugin creator trandoductin
-Eureka
( A new Member )

Eureka said


If it hasn't been answered yet, save your notepad text with an 'scm' file extension.
Then copy-n-paste or drag and drop into your Gimp 'scripts' folder.
You do the same thing with python scripts (py) and put them in the 'plug-ins' folder. (you may need to make them executable)

Dear Tas_mania,
Thanks for for your guidance.

-Eureka

I intended during lockdown to do quite a lot of drawing but ended up doing cooking and working on digital photography



I do appreciate this tutorial though



I thought the gimp head cut/ woodcut plug-in was good I don't know if it is round for later versions



I note people are doing artificial intelligence software for this kind of thing which makes sense as there is often too much information from photos; if done by hand ,drawing, it would be done simpler with some intelligent decisions. That said I used it for a well-known local scene and somebody whose house was on the pictures said they liked my interpretation I will tell her one day it was done from a photo



Artificial intelligence maybe gives more control but in creative things I often like to have less so I wonder if there could be something like the head cut plug-in which randomly simplifies and lots of variations could be tried

if there is another lockdown maybe I ought to go back to programming, not really done any for 20 years, and do a sort of variations filter which randomly simplifies

There is a half tone filter in GMIC qt. This was done just with default

Not as good as the tutorial by Pat David though for headcut.