Using FXSmooth on 1 bit image creates 24 bit

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fs051268
Posts: 35
Joined: Wed May 22, 2013 4:00 pm

Using FXSmooth on 1 bit image creates 24 bit

Post by fs051268 » Wed Mar 23, 2016 5:32 pm

Hi,

I am using the FxSmooth() function on a 1 bit image and afterwards the image bit depth is 24.
Why is that and how can I get back to the original bit depth?

David
Posts: 66
Joined: Mon Feb 08, 2016 3:12 pm

Re: Using FXSmooth on 1 bit image creates 24 bit

Post by David » Thu Mar 24, 2016 3:28 pm

Hi,

FxSmooth somehow changes the value of a pixel with kind of average values of the neighborhood. It usually make sense for color and greyscale images, it is not often used for black and white image. For black and white images, a pixel is either black, either white, there's no real place for averages.

Now if you still want to apply smooth and get a 1bpp image, you will have to make use of the ConvertTo1Bpp method: http://guides.gdpicture.com/content/web ... o1Bpp.html

Regards,

David

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Sephir
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Location: Germany
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Re: Using FXSmooth on 1 bit image creates 24 bit

Post by Sephir » Thu Nov 17, 2016 1:11 pm

The same Effect occurs with SharpenFX.... From Black/White Image with BitDepth 1 (95kb) result an RGB Image with BitDepth 24 ( = 1.2 MB) which is pretty heavy. Should Sharpening not "rerender" edges and make them more lineal ?

Cedric
Posts: 260
Joined: Sun Sep 02, 2012 7:30 pm

Re: Using FXSmooth on 1 bit image creates 24 bit

Post by Cedric » Fri Nov 18, 2016 11:00 am

That implies interpolation process which cannot happen on a 1bpp image since there is no other value but white or black hence the bitdepth increase.

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