[composer] add option to disable antialiasing when exporting compositions

[qgib]

Author Name: Giovanni Manghi (@gioman)
Original Redmine Issue: 9281

Redmine category:map_composer/printing

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To be more precise, it seems that when printing the option is set always as active, no matter if printing as raster or not.

[qgib]

Author Name: Jürgen Fischer (@jef-n)

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• subject was changed from The option "make lines apperar less jagged at the expense of some drawing performance" does not seems to be applied in the print composer to The option "make lines appear less jagged at the expense of some drawing performance" does not seems to be applied in the print composer

[qgib]

Author Name: Nyall Dawson (@nyalldawson)

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I don't think this is a bug - to me it's a feature. Why would you want to disable anti-aliasing when exporting a composition?

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• status_id was changed from Open to Feedback

[qgib]

Author Name: aperi2007 - (aperi2007 -)

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The antialiasing if no good for the black-white TIFF4 images.

In the tiff4 the main goal is have always only two color black/white.
The antialiasing work substituting some white pixel with a grey light color.
This break the possibility to have a tiff4 image.

As a use case:
the composer will allow the opportunity to export a map as a tiff georef.

But if the goal is to export a tiff4 black/white image.
The acutal setting of composer to deny the correct black/white will deny to have a set of tiff4 images georef as exportation from qgis.

[qgib]

Author Name: aperi2007 - (aperi2007 -)

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So it is definitively a bug because It donnot reproduce exactly what there is in the canvas.

The goal of composer is produce a print of what there is on canvas .
A composer that da another think differente from canvas is not a print in qgis, but a different program.
In the canvas there is a black/white image because I can put the white transparent and having a result when export.
In composer when export I have a raster not black/white.

So I guess it is a bug.

[qgib]

Author Name: Nyall Dawson (@nyalldawson)

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OK, that's a good point. However I don't think the existing option for antialiasing in settings is the correct solution. For one, this option is worded in a way that makes it sound like its purely for performance. I'd imagine the given how its worded the current use case is that people are disabling antialiasing in settings to speed up working with the canvas , not to change how maps are exported.
Secondly, this current setting has no effect on other composer controls such as labels, etc.
I think your use case could be better addressed by an option in the composition settings for disabling antialiasing for the whole composition. This option would be per composition, not a global setting.

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• category_id was changed from 33 to Map Composer/Printing
• tracker_id was changed from 1 to 2
• subject was changed from The option "make lines appear less jagged at the expense of some drawing performance" does not seems to be applied in the print composer to [composer] add option to disable antialiasing when exporting compositions

[qgib]

Author Name: Paolo Cavallini (@pcav)

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Sounds reasonable. Nevertheless, I think this option should be added, as without it the user case described is seriously hindered. As it solves a real user issue, quite important in massive production, and it should not impact other code, I would ask to reconsider adding it to the upcoming version.

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• priority_id was changed from Normal to High
• fixed_version_id was changed from Future Release - High Priority to Version 2.2

[qgib]

Author Name: Giovanni Manghi (@gioman)

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• fixed_version_id was changed from Version 2.2 to Version 2.4
• status_id was changed from Feedback to Open

[qgib]

Author Name: Jürgen Fischer (@jef-n)

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• fixed_version_id was changed from Version 2.4 to Future Release - High Priority

[qgib]

Author Name: Giovanni Manghi (@gioman)

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• easy_fix was configured as 0

[qgib]

Author Name: Nyall Dawson (@nyalldawson)

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Applied in changeset 2f0969e.

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• status_id was changed from Open to Closed
• done_ratio was changed from 0 to 100

[qgib]

Author Name: Giovanni Manghi (@gioman)

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• resolution was changed from to fixed/implemented