Gmic offers the filter
Layers > colours to layers

Which allows tuneable separation of colours

Minimal Area (%) may have to be kept very low (0.01 to 0.02) to receive a result.

On Fri, 13 Mar 2020, 12:00 , wrote:

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Today's Topics:

1. Open PDF at the right width and height (YouNoOat) 2. Open PDF at the right width and height (rich404) 3. Sizes of an image - display v printing (chuckie) 4. Open PDF at the right width and height (YouNoOat) 5. Re: Sizes of an image - display v printing (Ofnuts) 6. Decompose greyscale to layers (Quin Benson) 7. Gimp 2.10 and Streetwear font (glyphs) (vincents)

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Message: 1 Date: Thu, 12 Mar 2020 18:43:51 +0100 From: YouNoOat
To: gimp-user-list@gnome.org
Subject: [Gimp-user] Open PDF at the right width and height Message-ID:
Content-Type: text/plain; charset=UTF-8

Hello,

I'm trying to convert PDF to image with batch processing. But I didn't find a way to choose pixel-width and pixel-height during the opening of the PDF, as in interactive mode (window "import PDF").

Instead of that, Gimp automatically opens the PDF at 100% size AND 100 dpi.

For example : My PDF is 7,84 x 11,69 inch, not rasterized and fully losless resizable. As Gimp assumes that the PDF is at 100 dpi, the resulting image (opened with
"gimp_file_load") is 784 x 1169 pixels.

It's too low, because the PDF contains mainly small texts, not readable at 784 x
1169.

And the idea to use "gimp_image_scale" to increase the image size is not relevant.
It makes heavier images but not more readable. Once the image is rasterized, even with a good interpolation, you can't no more
increase the readability.

The plugin "file-pdf-load" neither have width/height or dpi parameters, so it
converts the PDF at the same small resolution (768 x 1169).

Could you help me to create large images from PDF by batch processing ?

Thank you - APL

-- YouNoOat (via www.gimpusers.com/forums)

------------------------------

Message: 2 Date: Thu, 12 Mar 2020 19:26:58 +0100 From: rich404
To: gimp-user-list@gnome.org
Subject: [Gimp-user] Open PDF at the right width and height Message-ID:
Content-Type: text/plain; charset=UTF-8

Hello,

I'm trying to convert PDF to image with batch processing. But I didn't find a way to choose pixel-width and pixel-height during the
opening of the PDF, as in interactive mode (window "import PDF").

Instead of that, Gimp automatically opens the PDF at 100% size AND 100 dpi.

For example :
My PDF is 7,84 x 11,69 inch, not rasterized and fully losless resizable.
As Gimp assumes that the PDF is at 100 dpi, the resulting image (opened with
"gimp_file_load") is 784 x 1169 pixels.

It's too low, because the PDF contains mainly small texts, not readable at 784 x
1169.

And the idea to use "gimp_image_scale" to increase the image size is not
relevant.
It makes heavier images but not more readable. Once the image is rasterized, even with a good interpolation, you can't no more
increase the readability.

The plugin "file-pdf-load" neither have width/height or dpi parameters, so it
converts the PDF at the same small resolution (768 x 1169).

Could you help me to create large images from PDF by batch processing ?

Thank you - APL

Did you ask this question on one of the Gimp forums recently, seems familiar.

However.

Do not use Gimp, use ImageMagick.

magick -density 300 infile.pdf -quality 100 outfile.png

and wrap that in a bash or batch file depending on OS.

-- rich404 (via www.gimpusers.com/forums)

------------------------------

Message: 3 Date: Thu, 12 Mar 2020 19:44:33 +0100 From: chuckie
To: gimp-user-list@gnome.org
Subject: [Gimp-user] Sizes of an image - display v printing Message-ID:
Content-Type: text/plain; charset=UTF-8

I am little confused ...

I have an image that is 828 pixels wide.

If I open it in Paint, and HyperSnap or GIMP and view it at 100% and use a ruler, the width of the image is about 23cm.

If I drag the image into a Microsoft Outlook email (embed it) or go to the GIMP
Print Size window, they both report it to be 3.5cm wide!

So, the GIMP editor shows it at a nice size of 23cm visually, but to print, or
embed it in Microsoft Outlook email it is only 3.5cm width.

Why is it then that the display of it in the editor is 23cm? What changes need
to be applied so that the image will embed into Microsoft Outlook email at 23cm?
Certainly, I was expectign it to embed at the scale I see it in the GIMP viewer
and not the anticipate scale for printing.

-- chuckie (via www.gimpusers.com/forums)

------------------------------

Message: 4 Date: Fri, 13 Mar 2020 00:47:39 +0100 From: YouNoOat
To: gimp-user-list@gnome.org
Subject: [Gimp-user] Open PDF at the right width and height Message-ID:
Content-Type: text/plain; charset=UTF-8

Did you ask this question on one of the Gimp forums recently, seems familiar.

However.

Do not use Gimp, use ImageMagick.

magick -density 300 infile.pdf -quality 100 outfile.png

and wrap that in a bash or batch file depending on OS.

Thank you Rich404,

This was my first post on this issue. If it seems familiar, perhaps it's because
it worries many people.
Surprising that on this subject Image Magic is better than Gimp. Lot of Developpers told me that Gimp have killed Image Magic ... Anyway Thank you a lot for your acurate answer.

-- YouNoOat (via www.gimpusers.com/forums)

------------------------------

Message: 5 Date: Fri, 13 Mar 2020 10:27:08 +0100 From: Ofnuts
To: gimp-user-list@gnome.org
Subject: Re: [Gimp-user] Sizes of an image - display v printing Message-ID:
Content-Type: text/plain; charset=iso-8859-15; format=flowed

On 12/03/2020 19:44, chuckie wrote:

I am little confused ...

I have an image that is 828 pixels wide.

If I open it in Paint, and HyperSnap or GIMP and view it at 100% and use

a

ruler, the width of the image is about 23cm.

If I drag the image into a Microsoft Outlook email (embed it) or go to

the GIMP

Print Size window, they both report it to be 3.5cm wide!

So, the GIMP editor shows it at a nice size of 23cm visually, but to

print, or

embed it in Microsoft Outlook email it is only 3.5cm width.

Why is it then that the display of it in the editor is 23cm? What

changes need

to be applied so that the image will embed into Microsoft Outlook email

at 23cm?

Certainly, I was expectign it to embed at the scale I see it in the GIMP

viewer

and not the anticipate scale for printing.

When you look at your picture at 100% in Gimp, Paint and other applications, it is displayed "dot for dot", one pixel of the picture is one pixel on your screen, and therefore it is displayed using your screen definition? (so given the size you report we can assume that the resolution of your display is 828/(23/2.54)=91 pixels/inch).

On the other hand your? picture has an embedded "print definition" which is used for printing, in your case 828/(3.5/2.54)=600 pixels/inch. This sets a theoretical size for the picture, size at which the picture is printed (as long as everything in the print stack abides to it).

Print definition (in Pixels/inch), print size (in inches) and size (in pixels) are related by the formula:

print size = print definition * pixels

Note that this means that you can only pick two of these values, the third is determined by the first two.

In Gimp you can un-tick "View>Dot for dot", in which case the picture will be shown at the print size, if your screen resolution is properly set? (see Edit>Preferences>Interface>Display).

When you create the image, you should set the size in pixels big enough so that you can print it at the required size with a print definition of at least 200 pixels/inch (photo) preferably 300 or more if there is text/logos or other computer-generated graphics. The advanced options in "File>New..." let you enter a print size and print definition, and compute the required size in pixels.

------------------------------

Message: 6 Date: Fri, 13 Mar 2020 09:29:14 +0000 From: Quin Benson
To: gimp-user-list@gnome.org
Subject: [Gimp-user] Decompose greyscale to layers Message-ID:

Content-Type: text/plain; charset="UTF-8"

Please can anybody suggest a script or plug-in that will decompose a posterized grayscale image to layers? Or, for that matter, posterize an image and then decompose the various shades to layers?

------------------------------

Message: 7 Date: Fri, 13 Mar 2020 11:16:54 +0100 From: vincents
To: gimp-user-list@gnome.org
Subject: [Gimp-user] Gimp 2.10 and Streetwear font (glyphs) Message-ID:
Content-Type: text/plain; charset=UTF-8

Hi All !

Thanks guys for your answers.

I will move to Photoshop/Illustrator for this time :( :( :(

Regards,

Vincent

-- vincents (via www.gimpusers.com/forums)

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