wkblify_band()

raster2pgsql.wkblify_band	(		options,
			band,
			level,
			xoff,
			yoff,
			read_block_size,
			block_size,
			infile,
			bandidx
	)

Writes band of given GDAL dataset into HEX-encoded WKB for WKT Raster output.

Definition at line 758 of file raster2pgsql.py.

def wkblify_band(options, band, level, xoff, yoff, read_block_size, block_size, infile, bandidx):
    """Writes band of given GDAL dataset into HEX-encoded WKB for WKT Raster output."""
    assert band is not None, "Error: Missing GDAL raster band"
 
    hexwkb = ''
    
    if options.register:
        # Off-db raster
        # TODO: Do we want to handle options.overview_level? --mloskot
        # ANSWER: 
        # TODO: Where bandidx and ds come from? --mloskot
        # ANSWER: Provided by caller method --jorgearevalo
        hexwkb += wkblify('B', bandidx - 1)
        filepath = os.path.abspath(infile.replace('\\', '\\\\'))
        logit('MSG: Out-db raster path=%s\n' % filepath)
        hexwkb += wkblify(str(len(filepath)) + 's', filepath)
        hexwkb += wkblify('B', 0)
    else:
        # In-db raster
 
        # Right most column and bottom most row of blocks have
        # portions that extend beyond the raster
        read_padding_size = calculate_block_pad_size(band, xoff, yoff, read_block_size)
        valid_read_block_size = ( read_block_size[0] - read_padding_size[0],
                                  read_block_size[1] - read_padding_size[1] )
 
 
        if read_padding_size[0] > 0 or read_padding_size[1] > 0:
            target_block_size = (valid_read_block_size[0] / level, valid_read_block_size[1] / level)
            target_padding_size = (read_padding_size[0] / level, read_padding_size[1] / level)
        else:
            target_block_size = block_size
            target_padding_size = ( 0, 0 )
 
        logit('MSG: Normalize read_block=%s for level=%d to valid_read_block=%s with padding=%s\n' % \
              (read_block_size, level, valid_read_block_size, read_padding_size))
        logit('MSG: Normalize target_block=%s for level=%d to valid_target_block=%s with padding=%s\n' % \
              (block_size, level, target_block_size, target_padding_size))
        logit('MSG: ReadAsArray( %d, %d, %s, %s)\n' % \
              (xoff, yoff, str(valid_read_block_size), str(target_block_size)))
 
        assert valid_read_block_size[0] > 0 and valid_read_block_size[1] > 0
        assert target_block_size[0] > 0 and target_block_size[1] > 0
 
        pixels = band.ReadAsArray(xoff, yoff, valid_read_block_size[0], valid_read_block_size[1],
                                  target_block_size[0], target_block_size[1])
 
        # XXX: Use for debugging only
        #dump_block_numpy(pixels)
 
        out_pixels = numpy.zeros((block_size[1], block_size[0]), pt2numpy(band.DataType))
 
        logit('MSG: Read valid source:\t%d x %d\n' % (len(pixels[0]), len(pixels)))
        logit('MSG: Write into block:\t%d x %d\n' % (len(out_pixels[0]), len(out_pixels)))
        
        if target_padding_size[0] > 0 or target_padding_size[1] > 0:
 
            ysize_read_pixels = len(pixels)
            nodata_value = fetch_band_nodata(band)
 
            # Apply columns padding
            pad_cols = numpy.array([nodata_value] * target_padding_size[0])
            for row in range (0, ysize_read_pixels):
                out_line = numpy.append(pixels[row], pad_cols)
                out_pixels[row] = out_line
 
            # Fill rows padding with nodata value
            for row in range(ysize_read_pixels, ysize_read_pixels + target_padding_size[1]):
                out_pixels[row].fill(nodata_value)
        else:
            out_pixels = pixels
 
        # XXX: Use for debugging only
        #dump_block_numpy(out_pixels)
 
        hexwkb = binascii.hexlify(out_pixels)
 
    check_hex(hexwkb)
    return hexwkb