def perform_subset(self,
src_ds,
range_type,
subset_rect,
dst_rect,
rangesubset=None):
vrt = VRTBuilder(*subset_rect.size)
input_bands = list(range_type)
# list of band indices/names. defaults to all bands
if rangesubset:
subset_bands = rangesubset.get_band_indices(range_type, 1)
else:
subset_bands = xrange(1, len(range_type) + 1)
for dst_index, src_index in enumerate(subset_bands, start=1):
input_band = input_bands[src_index - 1]
vrt.add_band(input_band.data_type)
vrt.add_simple_source(dst_index, src_ds, src_index, subset_rect,
dst_rect)
vrt.copy_metadata(src_ds)
vrt.copy_gcps(src_ds, subset_rect)
return vrt.dataset
def get_source_dataset(self, coverage, data_items, range_type):
if len(data_items) == 1:
return gdal.OpenShared(abspath(connect(data_items[0])))
else:
vrt = VRTBuilder(coverage.size_x,
coverage.size_y,
vrt_filename=temp_vsimem_filename())
# sort in ascending order according to semantic
data_items = sorted(data_items, key=(lambda d: d.semantic))
gcps = []
compound_index = 0
for data_item in data_items:
path = abspath(connect(data_item))
# iterate over all bands of the data item
for set_index, item_index in self._data_item_band_indices(
data_item):
if set_index != compound_index + 1:
raise ValueError
compound_index = set_index
band = range_type[set_index]
vrt.add_band(band.data_type)
vrt.add_simple_source(set_index, path, item_index)
return vrt.dataset
def get_source_and_dest_rect(self, dataset, subsets):
size_x, size_y = dataset.RasterXSize, dataset.RasterYSize
image_rect = Rect(0, 0, size_x, size_y)
if not subsets:
subset_rect = image_rect
# pixel subset
elif subsets.srid is None: # means "imageCRS"
minx, miny, maxx, maxy = subsets.xy_bbox
minx = int(minx) if minx is not None else image_rect.offset_x
miny = int(miny) if miny is not None else image_rect.offset_y
maxx = int(maxx) if maxx is not None else image_rect.upper_x
maxy = int(maxy) if maxy is not None else image_rect.upper_y
subset_rect = Rect(minx, miny, maxx - minx + 1, maxy - miny + 1)
# subset in geographical coordinates
else:
vrt = VRTBuilder(*image_rect.size)
vrt.copy_gcps(dataset)
options = reftools.suggest_transformer(dataset)
subset_rect = reftools.rect_from_subset(vrt.dataset, subsets.srid,
*subsets.xy_bbox,
**options)
# check whether or not the subsets intersect with the image
if not image_rect.intersects(subset_rect):
raise RenderException("Subset outside coverage extent.", "subset")
src_rect = subset_rect #& image_rect # TODO: why no intersection??
dst_rect = src_rect - subset_rect.offset
return src_rect, dst_rect
