[gentoo-user] [OT?]: In search of a program to do different b/w dithering methods

[gentoo-user] [OT?]: In search of a program to do different b/w dithering methods

[tuxic]

Hi,

Happy New Year!!!

the programmable pocket calculator "DM42" offers OFFIMAGES,
which will be displayed, when the calculator is switched off.

The display is pure black and white.

For displaying (the illusion of) different shades of gray, one need
to convert the colored image into a so called "dithered" black and
white image (newspapers often use this trick).
Since -- in difference to the newspapers -- the pixels all have the
same size and can only be switched on or off only a few dithering
methods can be applied from which I want to choose the best suited
for a certain image.

The only problem: Which software can do this kind of conversion?

Thanks a lot for any help in advance!
Cheers
Meino

Re: [gentoo-user] [OT?]: In search of a program to do different b/w dithering methods

[Frank Steinmetzger]

On Mon, Jan 01, 2018 at 09:24:46PM +0100, tuxic@posteo.de wrote:
> Hi,
> […]
> For displaying (the illusion of) different shades of gray, one need
> to convert the colored image into a so called "dithered" black and
> white image (newspapers often use this trick).
> Since -- in difference to the newspapers -- the pixels all have the
> same size and can only be switched on or off only a few dithering
> methods can be applied from which I want to choose the best suited
> for a certain image.
>
> The only problem: Which software can do this kind of conversion?

The obvious answer Gimp has three methods. Open your photo, select Image →
Mode → Indexed. Select 1 bit colour depth and choose between the dithering
methods at the bottom of the dialog.

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Re: [gentoo-user] [OT?]: In search of a program to do different b/w dithering methods

[tuxic]

On 01/01 10:34, Frank Steinmetzger wrote:
> On Mon, Jan 01, 2018 at 09:24:46PM +0100, tuxic@posteo.de wrote:
> > Hi,
> > […]
> > For displaying (the illusion of) different shades of gray, one need
> > to convert the colored image into a so called "dithered" black and
> > white image (newspapers often use this trick).
> > Since -- in difference to the newspapers -- the pixels all have the
> > same size and can only be switched on or off only a few dithering
> > methods can be applied from which I want to choose the best suited
> > for a certain image.
> >
> > The only problem: Which software can do this kind of conversion?
> 
> The obvious answer Gimp has three methods. Open your photo, select Image →
> Mode → Indexed. Select 1 bit colour depth and choose between the dithering
> methods at the bottom of the dialog.
> 
> -- 
> Gruß | Greetings | Qapla’
> Please do not share anything from, with or about me on any social network.
> 
> The bad thing about Wikipedia jokes is
> - Deleted due to lack of relevance. -
> 

Hi Frank,

thanks for your help! :)
Yes, Gimp would be one possibility...but I forgot to mention, that
I am looking for a command line tool...
I want to do 'mass dithering' and want neither a gui nor a 
heavy program like The Gimp.

I checked pbmplus and found no useful part for that porpuse...

Cheers
Meino

Re: [gentoo-user] [OT?]: In search of a program to do different b/w dithering methods

[Adam Carter]

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>
> I am looking for a command line tool...
> I want to do 'mass dithering' and want neither a gui nor a
> heavy program like The Gimp.
>
> I checked pbmplus and found no useful part for that porpuse...
>

Does this do what you want? Its installed by default with imagemagick

http://www.imagemagick.org/script/convert.php

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[gentoo-user] Re: [OT?]: In search of a program to do different b/w dithering methods

[Grant Edwards]

On 2018-01-02, Adam Carter <adamcarter3@gmail.com> wrote:
>>
>> I am looking for a command line tool...
>> I want to do 'mass dithering' and want neither a gui nor a
>> heavy program like The Gimp.
>>
>> I checked pbmplus and found no useful part for that porpuse...
>
> Does this do what you want? Its installed by default with imagemagick
>
> http://www.imagemagick.org/script/convert.php

Indeed.  Anytime you want to do anything via command line with
bitmapped graphics, the first place you look is Imagemagick:

 http://www.imagemagick.org/Usage/quantize/

Or more specifically

 http://www.imagemagick.org/Usage/quantize/#monochrome

If you don't find what you want in Imagemagick, the second place you
look is Imagemagick -- it's probably there and you missed it the first
time.

-- 
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                                  at               lease!!
                              gmail.com            

[gentoo-user] Re: In search of a program to do different b/w dithering methods

[Ian Zimmerman]

On 2018-01-02 15:57, Grant Edwards wrote:

> If you don't find what you want in Imagemagick, the second place you
> look is Imagemagick -- it's probably there and you missed it the first
> time.

And the third place you look is Graphicsmagick :-)

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[gentoo-user] Re: In search of a program to do different b/w dithering methods

[Grant Edwards]

On 2018-01-02, Ian Zimmerman <itz@very.loosely.org> wrote:
> On 2018-01-02 15:57, Grant Edwards wrote:
>
>> If you don't find what you want in Imagemagick, the second place you
>> look is Imagemagick -- it's probably there and you missed it the first
>> time.
>
> And the third place you look is Graphicsmagick :-)

Ah yes, I had forgotten aboug Graphicsmagick.  I vaguely remember
having to install it alongside imagemagick for some reason many years
ago...

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Grant Edwards               grant.b.edwards        Yow! Now I am depressed ...
                                  at               
                              gmail.com