How to make a picture black and white?

[danzibr]

And by black and white I mean just black and just white, no gray. I don't know if there's an art term for this. I'm thinking like the face in this picture

Spoiler: Picture

Show

Problem is, I don't even know how to google this. "how to make a picture black and white" doesn't give me the results I want. Any suggestions?

Thanks!

[Iruka]

Searching for stuff like "two colour picture" or "duotone" might lead you into the right direction.
Quick and dirty: Convert the picture to grayscale and then increase the contrast to the maximum. This just leaves black and white. It will however be not as "clean" as your example.

Spoiler: Example

Show

You can play around with the brightness to influence which areas end up white and which black.

edit: "posterization" might also be a helpful search term

[Jasdoif]

GIMP and Photoshop have a Threshold function/filter, which converts pixels to black or white based on their brightness. Is that the kind of thing you mean?

[danzibr]

Searching for stuff like "two colour picture" or "duotone" might lead you into the right direction.
Quick and dirty: Convert the picture to grayscale and then increase the contrast to the maximum. This just leaves black and white. It will however be not as "clean" as your example.

Spoiler: Example

Show

You can play around with the brightness to influence which areas end up white and which black.

edit: "posterization" might also be a helpful search term

Ahh I see. Good vocab there. Thanks.

GIMP and Photoshop have a Threshold function/filter, which converts pixels to black or white based on their brightness. Is that the kind of thing you mean?

EXACTLY! Thanks!

Normally I hate seeing/typing this, but... /thread

[kentran]

Searching for stuff like "two colour picture" or "duotone" might lead you into the right direction.
Quick and dirty: Convert the picture to grayscale and then increase the contrast to the maximum. This just leaves black and white. It will however be not as "clean" as your example.

Spoiler: Example

Show

You can play around with the brightness to influence which areas end up white and which black.

edit: "posterization" might also be a helpful search term

The answer is great.

[raaaahman]

Hi, my 2 cents:

You don't want strict black & white, but rather high contrast grayscale.

The explanation: what you perceive black & white has in fact subtle gradient on its border that blend with the white space, at least on computer screens. If you ask a software "black&white" you will have only full white (maximum values of the red green and blue lights) or full black (minimal rgb values), which will lead to what we call "aliasing": the stair alike effects on lines.

The best way to play with it in softwares like photoshop is to move the "levels" cursors, which will modify the range of the values (you must first have your image in grayscale).

If you lack homogeneity in your black zones, you may add some blur effects (from filter) then play with the levels again, you'll lose details and sharpness but can have a more cleaned piece.