sanya-dbms/processing/algs/gdal/rgb2pct.py

"""
***************************************************************************
    rgb2pct.py
    ---------------------
    Date                 : August 2012
    Copyright            : (C) 2012 by Victor Olaya
    Email                : volayaf at gmail dot com
***************************************************************************
*                                                                         *
*   This program is free software; you can redistribute it and/or modify  *
*   it under the terms of the GNU General Public License as published by  *
*   the Free Software Foundation; either version 2 of the License, or     *
*   (at your option) any later version.                                   *
*                                                                         *
***************************************************************************
"""

__author__ = 'Victor Olaya'
__date__ = 'August 2012'
__copyright__ = '(C) 2012, Victor Olaya'

import os

from qgis.PyQt.QtGui import QIcon

from qgis.core import (QgsRasterFileWriter,
                       QgsProcessingException,
                       QgsProcessingParameterRasterLayer,
                       QgsProcessingParameterNumber,
                       QgsProcessingParameterRasterDestination)
from processing.algs.gdal.GdalAlgorithm import GdalAlgorithm
from processing.algs.gdal.GdalUtils import GdalUtils
from processing.tools.system import isWindows

pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]


class rgb2pct(GdalAlgorithm):
    INPUT = 'INPUT'
    OUTPUT = 'OUTPUT'
    NCOLORS = 'NCOLORS'

    def __init__(self):
        super().__init__()

    def initAlgorithm(self, config=None):
        self.addParameter(QgsProcessingParameterRasterLayer(self.INPUT, self.tr('Input layer')))
        self.addParameter(QgsProcessingParameterNumber(self.NCOLORS,
                                                       self.tr('Number of colors'),
                                                       type=QgsProcessingParameterNumber.Integer,
                                                       minValue=0,
                                                       maxValue=255,
                                                       defaultValue=2))

        self.addParameter(QgsProcessingParameterRasterDestination(self.OUTPUT, self.tr('RGB to PCT')))

    def name(self):
        return 'rgbtopct'

    def displayName(self):
        return self.tr('RGB to PCT')

    def group(self):
        return self.tr('Raster conversion')

    def groupId(self):
        return 'rasterconversion'

    def icon(self):
        return QIcon(os.path.join(pluginPath, 'images', 'gdaltools', '24-to-8-bits.png'))

    def commandName(self):
        return 'rgb2pct'

    def getConsoleCommands(self, parameters, context, feedback, executing=True):
        out = self.parameterAsOutputLayer(parameters, self.OUTPUT, context)
        self.setOutputValue(self.OUTPUT, out)

        raster = self.parameterAsRasterLayer(parameters, self.INPUT, context)
        if raster is None:
            raise QgsProcessingException(self.invalidRasterError(parameters, self.INPUT))

        output_format = QgsRasterFileWriter.driverForExtension(os.path.splitext(out)[1])
        if not output_format:
            raise QgsProcessingException(self.tr('Output format is invalid'))

        arguments = [
            '-n',
            str(self.parameterAsInt(parameters, self.NCOLORS, context)),
            '-of',
            output_format,
            raster.source(),
            out
        ]

        return [self.commandName() + ('.bat' if isWindows() else '.py'), GdalUtils.escapeAndJoin(arguments)]