Transparency band not persisted in QgsProject

[qgib]

Author Name: Tim Sutton (Tim Sutton)
Original Redmine Issue: 4953
Affected QGIS version: master
Redmine category:rasters
Assignee: Tim Sutton

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When using a single band raster and setting the tranparency band to band 1, the transparency is correctly applied. However when closing and then reopening the project, the layer transparency band reverts to 'Not Set'.

Expected behaviour:

The transparency band state should be properly restored to band 1 when the project is opened.

[qgib]

Author Name: Paolo Cavallini (@pcav)

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• fixed_version_id was changed from Version 1.7.4 to Version 1.8.0

[qgib]

Author Name: Paolo Cavallini (@pcav)

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• fixed_version_id was changed from Version 1.8.0 to Version 2.0.0

[qgib]

Author Name: Homme Zwaagstra (Homme Zwaagstra)

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This is an issue for me in QGIS 1.8.0. Whichever band is selected as the transparency band it is not persisted in the .qgs project file. The following is the map layer corresponding to a grayscale TIF whose alpha band I am trying to set as the transparent band:

<maplayer minimumScale="0" maximumScale="1e+08" type="raster" hasScaleBasedVisibilityFlag="0">
    <id>hillshade20121025100031179</id>
    <datasource>./hillshade.tif</datasource>
    <title></title>
    <abstract></abstract>
    <layername>hillshade</layername>
    <srs>
        <spatialrefsys>
            <proj4>+proj=longlat +datum=WGS84 +no_defs</proj4>
            <srsid>3452</srsid>
            <srid>4326</srid>
            <authid>EPSG:4326</authid>
            <description>WGS 84</description>
            <projectionacronym>longlat</projectionacronym>
            <ellipsoidacronym>WGS84</ellipsoidacronym>
            <geographicflag>true</geographicflag>
        </spatialrefsys>
    </srs>
    <transparencyLevelInt>62</transparencyLevelInt>
    <customproperties/>
    <provider>gdal</provider>
    <rasterproperties>
        <mDrawingStyle>MultiBandSingleBandGray</mDrawingStyle>
        <mColorShadingAlgorithm>UndefinedShader</mColorShadingAlgorithm>
        <mInvertColor boolean="false"/>
        <mRedBandName>Band 1</mRedBandName>
        <mGreenBandName>Band 2</mGreenBandName>
        <mBlueBandName>Band 2</mBlueBandName>
        <mGrayBandName>Band 1</mGrayBandName>
        <mStandardDeviations>0</mStandardDeviations>
        <mUserDefinedRGBMinimumMaximum boolean="false"/>
        <mRGBMinimumMaximumEstimated boolean="true"/>
        <mUserDefinedGrayMinimumMaximum boolean="false"/>
        <mGrayMinimumMaximumEstimated boolean="true"/>
        <mContrastEnhancementAlgorithm>NoEnhancement</mContrastEnhancementAlgorithm>
        <contrastEnhancementMinMaxValues>
            <minMaxEntry>
                <min>0</min>
                <max>255</max>
            </minMaxEntry>
            <minMaxEntry>
                <min>0</min>
                <max>255</max>
            </minMaxEntry>
        </contrastEnhancementMinMaxValues>
        <mNoDataValue mValidNoDataValue="true">-32768.000000</mNoDataValue>
        <singleValuePixelList>
            <pixelListEntry pixelValue="-32768.000000" percentTransparent="100"/>
        </singleValuePixelList>
        <threeValuePixelList>
            <pixelListEntry red="-32768.000000" blue="-32768.000000" green="-32768.000000" percentTransparent="100"/>
        </threeValuePixelList>
    </rasterproperties>
</maplayer>

[qgib]

Author Name: Giovanni Manghi (@gioman)

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Homme Zwaagstra wrote:

This is an issue for me in QGIS 1.8.0. Whichever band is selected as the transparency band it is not persisted in the .qgs project file. The following is the map layer corresponding to a grayscale TIF whose alpha band I am trying to set as the transparent band:

[...]

have you tested qgis master? many things changed in rasters in qgis master... please try and leave feedback.

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• status_id was changed from Open to Feedback
• operating_system was changed from all to

[qgib]

Author Name: Homme Zwaagstra (Homme Zwaagstra)

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Giovanni Manghi wrote:

have you tested qgis master? many things changed in rasters in qgis master... please try and leave feedback.

I have tested in qgis master against commit a27aad0 (1.9.0 Alpha) and it seems to have fixed the issue - thanks!

[qgib]

Author Name: Giovanni Manghi (@gioman)

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• resolution was changed from to fixed
• status_id was changed from Feedback to Closed