Source code for rios.imagewriter

Contains the ImageWriter class

# This file is part of RIOS - Raster I/O Simplification
# Copyright (C) 2012  Sam Gillingham, Neil Flood
# 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 3 of the License, or
# (at your option) any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# GNU General Public License for more details.
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <>.

from __future__ import print_function, division

import os
import math

from osgeo import gdal
from osgeo import gdal_array

from . import rioserrors
from . import rat
from . import calcstats
from . import fileinfo

[docs]def setDefaultDriver(): """ Sets some default values into global variables, defining what defaults we should use for GDAL driver. On any given output file these can be over-ridden, and can be over-ridden globally using the environment variables * $RIOS_DFLT_DRIVER * $RIOS_DFLT_DRIVEROPTIONS * $RIOS_DFLT_CREOPT_<drivername> If RIOS_DFLT_DRIVER is set, then it should be a gdal short driver name. If RIOS_DFLT_DRIVEROPTIONS is set, it should be a space-separated list of driver creation options, e.g. "COMPRESS=LZW TILED=YES", and should be appropriate for the selected GDAL driver. This can also be 'None' in which case an empty list of creation options is passed to the driver. The same rules apply to the driver-specific creation options given using $RIOS_DFLT_CREOPT_<driver>. These options are a later paradigm, and are intended to supercede the previous generic driver defaults. If not otherwise supplied, the default is to use the HFA driver, with compression. The code here is more complex than desirable, because it copes with legacy behaviour in the absence of the environment variables, and in the absence of the driver-specific option variables. """ global DEFAULTDRIVERNAME, DEFAULTCREATIONOPTIONS DEFAULTDRIVERNAME = os.getenv('RIOS_DFLT_DRIVER', default='HFA') creationOptionsStr = os.getenv('RIOS_DFLT_DRIVEROPTIONS') if creationOptionsStr is not None: if creationOptionsStr == 'None': # hack for KEA which needs no creation options # and LoadLeveler which deletes any env variables # set to an empty values DEFAULTCREATIONOPTIONS = [] else: DEFAULTCREATIONOPTIONS = creationOptionsStr.split() else: # To cope with the old behaviour, set something sensible for HFA, but not # otherwise if DEFAULTDRIVERNAME == "HFA": DEFAULTCREATIONOPTIONS = ['COMPRESSED=TRUE', 'IGNOREUTM=TRUE'] else: DEFAULTCREATIONOPTIONS = [] # In the new paradigm, default creation options are specific to each driver, and # are loaded into a dictionary global dfltDriverOptions dfltDriverOptions = {} # Start with the old generic default options, applied to the default driver dfltDriverOptions[DEFAULTDRIVERNAME] = DEFAULTCREATIONOPTIONS # Load some others which we wish to have as defaults, even if not set by the environment dfltDriverOptions['GTiff'] = ['TILED=YES', 'COMPRESS=LZW', 'INTERLEAVE=BAND', 'BIGTIFF=IF_SAFER'] # Now load any which are specified by environment variables, of the # form RIOS_DFLT_CREOPT_<drivername> driverOptVarPrefix = 'RIOS_DFLT_CREOPT_' for varname in os.environ: if varname.startswith(driverOptVarPrefix): drvrName = varname[len(driverOptVarPrefix):] optionsStr = os.getenv(varname) if optionsStr == 'None': # Repeat that ridiculous hack for the KEA/LoadLeveler combination dfltDriverOptions[drvrName] = [] else: dfltDriverOptions[drvrName] = optionsStr.split()
[docs]def allnotNone(items): for i in items: if i is None: return False return True
[docs]def anynotNone(items): for i in items: if i is not None: return True return False
[docs]class ImageWriter(object): """ This class is the opposite of the ImageReader class and is designed to be used in conjunction. The easiest way to use it is pass the info returned by the ImageReader for first iteration to the constructor. Otherwise, image size etc must be passed in. The write() method can be used to write a block (numpy array)at a time to the output image - this is designed to be used at each iteration through the ImageReader object. Otherwise, the writeAt() method can be used to write blocks to arbitary locations. **Example** :: import sys from rios.imagereader import ImageReader from rios.imagewriter import ImageWriter inputs = [sys.argv[1],sys.argv[2]] reader = ImageReader(inputs) writer = None for (info, blocks) in reader: block1,block2 = blocks out = block1 * 4 + block2 if writer is None: writer = ImageWriter(sys.argv[3],info=info, firstblock=out) else: writer.write(out) writer.close(calcStats=True) """ def __init__(self, filename, drivername=DEFAULTDRIVERNAME, creationoptions=None, nbands=None, gdaldatatype=None, firstblock=None, info=None, xsize=None, ysize=None, transform=None, projection=None, windowxsize=None, windowysize=None, overlap=None): """ filename is the output file to be created. Set driver to name of GDAL driver, default it HFA. creationoptions will also need to be set if not using HFA since the default probably does not make sense for other drivers. Either pass nbands and gdaldatatype OR firstblock. If you pass firstblock, nbands and gdaldataype will be determined from that block and that block written to file. Also, either pass info (the first argument returned from each iteration through ImageReader, generally create this class on the first iteration) or xsize, ysize, transform, projection, windowxsize, windowysize and overlap If you pass info, these other values will be determined from that """ self.filename = filename noninfoitems = [xsize, ysize, transform, projection, windowxsize, windowysize, overlap] if info is None: # check we have the other args if not allnotNone(noninfoitems): msg = 'If not passing info object, must pass all other image info' raise rioserrors.ParameterError(msg) # just save these values directly self.overlap = overlap self.windowxsize = windowxsize self.windowysize = windowysize self.xtotalblocks = int(math.ceil(float(xsize) / windowxsize)) self.ytotalblocks = int(math.ceil(float(ysize) / windowysize)) else: if anynotNone(noninfoitems): msg = 'Passed info object, but other args not None' raise rioserrors.ParameterError(msg) # grab what we need from the info object (xsize, ysize) = info.getTotalSize() transform = info.getTransform() projection = info.getProjection() (self.windowxsize, self.windowysize) = info.getWindowSize() self.overlap = info.getOverlapSize() (self.xtotalblocks, self.ytotalblocks) = info.getTotalBlocks() if firstblock is None and not allnotNone([nbands, gdaldatatype]): msg = 'if not passing firstblock, must pass nbands and gdaltype' raise rioserrors.ParameterError(msg) elif firstblock is not None and anynotNone([nbands, gdaldatatype]): msg = 'Must pass one either firstblock or nbands and gdaltype, not all of them' raise rioserrors.ParameterError(msg) if firstblock is not None: # RIOS only works with 3-d image arrays, where the first dimension is # the number of bands. Check that this is what the user gave us to write. if len(firstblock.shape) != 3: raise rioserrors.ArrayShapeError( "Shape of array to write must be 3-d. Shape is actually %s"%repr(firstblock.shape)) # get the number of bands out of the block (nbands, y, x) = firstblock.shape # and the datatype gdaldatatype = gdal_array.NumericTypeCodeToGDALTypeCode(firstblock.dtype) if creationoptions is None: if drivername in dfltDriverOptions: creationoptions = dfltDriverOptions[drivername] else: creationoptions = [] creationoptions = self.doubleCheckCreationOptions(drivername, creationoptions) self.deleteIfExisting(filename) # Create the output dataset driver = gdal.GetDriverByName(drivername) self.ds = driver.Create(str(filename), xsize, ysize, nbands, gdaldatatype, creationoptions) if self.ds is None: msg = 'Unable to create output file %s' % filename raise rioserrors.ImageOpenError(msg) self.ds.SetProjection(projection) self.ds.SetGeoTransform(transform) # start writing at the first block self.blocknum = 0 # if we have a first block then write it if firstblock is not None: self.write(firstblock)
[docs] @staticmethod def deleteIfExisting(filename): """ Delete the filename if it already exists. If possible, use the appropriate GDAL driver to do so, to ensure that any associated files will also be deleted. """ if os.path.exists(filename): # Save the current exception-use state usingExceptions = gdal.GetUseExceptions() if not usingExceptions: gdal.UseExceptions() # Try opening it for read, to find out whether it is # a valid GDAL file, and which driver it goes with try: ds = gdal.Open(str(filename)) except RuntimeError: ds = None finally: # Restore exception-use state if not usingExceptions: gdal.DontUseExceptions() if ds is not None: # It is apparently a valid GDAL file, so get the driver appropriate for it. drvr = ds.GetDriver() del ds # Use this driver to delete the file drvr.Delete(filename) else: # Apparently not a valid GDAL file, for whatever reason, so just remove the file # directly. os.remove(filename)
[docs] def getGDALDataset(self): """ Returns the underlying GDAL dataset object """ return self.ds
[docs] def getCurrentBlock(self): """ Returns the number of the current block """ return self.blocknum
[docs] def setThematic(self): """ Sets the output file to thematic. If file is multi-layer, then all bands are set to thematic. """ for i in range(1, self.ds.RasterCount + 1): band = self.ds.GetRasterBand(i) band.SetMetadataItem('LAYER_TYPE', 'thematic')
[docs] def setLayerNames(self, names): """ Sets the output layer names. Pass a list of layer names, one for each output band """ bandindex = 1 for name in names: bh = self.ds.GetRasterBand(bandindex) bh.SetDescription(name) bandindex += 1
[docs] def write(self, block): """ Writes the numpy block to the current location in the file, and updates the location pointer for next write """ # convert the block to row/column yblock = self.blocknum // self.xtotalblocks xblock = self.blocknum % self.xtotalblocks # calculate the coords of this block in pixels xcoord = xblock * self.windowxsize ycoord = yblock * self.windowysize self.writeAt(block, xcoord, ycoord) # so next time we write the next block self.blocknum += 1
[docs] def writeAt(self, block, xcoord, ycoord): """ writes the numpy block to the specified pixel coords in the file """ # check they asked for block is valid brxcoord = xcoord + block.shape[-1] - self.overlap * 2 brycoord = ycoord + block.shape[-2] - self.overlap * 2 if brxcoord > self.ds.RasterXSize or brycoord > self.ds.RasterYSize: raise rioserrors.OutsideImageBoundsError() # check they did actually pass a 3d array # (all arrays are 3d now - PyModeller had 2 and 3d) if block.ndim != 3: raise rioserrors.ParameterError("Only 3 dimensional arrays are accepted now") # write each band for band in range(self.ds.RasterCount): bh = self.ds.GetRasterBand(band + 1) slice_bottomMost = block.shape[-2] - self.overlap slice_rightMost = block.shape[-1] - self.overlap # take off overlap if present outblock = block[band, self.overlap:slice_bottomMost, self.overlap:slice_rightMost] bh.WriteArray(outblock, xcoord, ycoord)
[docs] def reset(self): """ Resets the location pointer so that the next write() call writes to the start of the file again """ self.blocknum = 0
[docs] def close(self, calcStats=False, statsIgnore=None, progress=None, omitPyramids=False, overviewLevels=calcstats.DEFAULT_OVERVIEWLEVELS, overviewMinDim=calcstats.DEFAULT_MINOVERVIEWDIM, overviewAggType=None, autoColorTableType=rat.DEFAULT_AUTOCOLORTABLETYPE, approx_ok=False): """ Closes the open dataset """ if statsIgnore is not None: # This also gets set inside addStatistics. That is a # historical anomaly. This is the correct place to do it. calcstats.setNullValue(self.ds, statsIgnore) if calcStats: from .cuiprogress import SilentProgress if progress is None: progress = SilentProgress() if not omitPyramids: calcstats.addPyramid(self.ds, progress, minoverviewdim=overviewMinDim, levels=overviewLevels, aggregationType=overviewAggType) calcstats.addStatistics(self.ds, progress, statsIgnore, approx_ok=approx_ok) self.ds.FlushCache() del self.ds self.ds = None # Check whether we will need to add an auto color table if autoColorTableType is not None: # Does nothing if layers are not thematic self.addAutoColorTable(autoColorTableType)
[docs] def addAutoColorTable(self, autoColorTableType): """ If autoColorTable has been set up for this output, then generate a color table of the requested type, and add it to the current file. This is called AFTER the Dataset has been closed, so is performed on the filename. This only applies to thematic layers, so when we open the file and find that the layers are athematic, we do nothing. """ imgInfo = fileinfo.ImageInfo(self.filename) if imgInfo.layerType == "thematic": imgStats = fileinfo.ImageFileStats(self.filename) ds = gdal.Open(self.filename, gdal.GA_Update) for i in range(imgInfo.rasterCount): numEntries = int(imgStats[i].max + 1) clrTbl = rat.genColorTable(numEntries, autoColorTableType) band = ds.GetRasterBand(i + 1) ratObj = band.GetDefaultRAT() redIdx, redNew = calcstats.findOrCreateColumn(ratObj, gdal.GFU_Red, "Red", gdal.GFT_Integer) greenIdx, greenNew = calcstats.findOrCreateColumn(ratObj, gdal.GFU_Green, "Green", gdal.GFT_Integer) blueIdx, blueNew = calcstats.findOrCreateColumn(ratObj, gdal.GFU_Blue, "Blue", gdal.GFT_Integer) alphaIdx, alphaNew = calcstats.findOrCreateColumn(ratObj, gdal.GFU_Alpha, "Alpha", gdal.GFT_Integer) # were any of these not already existing? if redNew or greenNew or blueNew or alphaNew: ratObj.WriteArray(clrTbl[:, 0], redIdx) ratObj.WriteArray(clrTbl[:, 1], greenIdx) ratObj.WriteArray(clrTbl[:, 2], blueIdx) ratObj.WriteArray(clrTbl[:, 3], alphaIdx) if not ratObj.ChangesAreWrittenToFile(): band.SetDefaultRAT(ratObj)
[docs] def doubleCheckCreationOptions(self, drivername, creationoptions): """ Try to ensure that the given creation options are not incompatible with RIOS operations. Does not attempt to ensure they are totally valid, as that is GDAL's job. Returns a copy of creationoptions, possibly modified, or raises ImageOpenError in cases where the problem is not fixable. """ newCreationoptions = creationoptions if drivername == 'GTiff': # The GDAL GTiff driver is incapable of reclaiming space within the file. This means that # if a block is re-written, then the space already used is left dangling, and the total # file size gets larger accordingly. If the RIOS block size is not a multiple of the # TIFF block size, then each RIOS block will require the re-writing of at least one # TIFF block (usually several). This turns out to be a disaster for file sizes. So, # here, we do our best to check these things, and prevent such a result. # The recommended configuration is that the $RIOS_DFLT_BLOCKXSIZE and # $RIOS_DFLT_BLOCKYSIZE be set to a power of 2, and everything else will follow. tiffBlockX = None tiffBlockY = None riosBlockX = self.windowxsize riosBlockY = self.windowysize # First copy the existing options, but keep aside any explicitly specified block size newCreationoptions = [] for optStr in creationoptions: if optStr[:11] == 'BLOCKXSIZE=': tiffBlockX = int(optStr[11:]) elif optStr[:11] == 'BLOCKYSIZE=': tiffBlockY = int(optStr[11:]) else: newCreationoptions.append(optStr) # If no tiff blocksizes were explictly requested, then set them the same as the # RIOS block sizes resettingTiffBlocksize = False if tiffBlockX is None: tiffBlockX = riosBlockX resettingTiffBlocksize = True if tiffBlockY is None: tiffBlockY = riosBlockY resettingTiffBlocksize = True # Require that tiff block sizes be a factor of the RIOS block size, so that whole # TIFF blocks are always written exactly once, with no re-writing. if (((riosBlockX % tiffBlockX) != 0) or ((riosBlockY % tiffBlockY) != 0)): msg = "GTiff block sizes {} should be factors of RIOS block sizes {}, ".format( (tiffBlockX, tiffBlockY), (riosBlockX, riosBlockY)) msg += "otherwise vast amounts of space are wasted rewriting blocks which are not reclaimed. " raise rioserrors.ImageOpenError(msg) # The GDAL GTiff driver will complain if GTiff block sizes are not powers of 2 def isPowerOf2(n): return (((n - 1) & n) == 0) if not (isPowerOf2(tiffBlockX) and isPowerOf2(tiffBlockY)): msg = "GTiff block sizes are {}. Must be powers of 2. ".format((tiffBlockX, tiffBlockY)) if resettingTiffBlocksize: msg += "GTiff block size(s) have been reset to match RIOS block sizes, so recommend adjusting RIOS block sizes. " else: msg += "Recommend resetting explicit GTiff block sizes. " raise rioserrors.ImageOpenError(msg) # Now append what we want the block size to be. newCreationoptions.append('BLOCKXSIZE={}'.format(self.windowxsize)) newCreationoptions.append('BLOCKYSIZE={}'.format(self.windowysize)) return newCreationoptions