def get_colormap() -> str:
"""Get a colormap mapping pixel values to colors
---
get:
summary: /colormap
description:
Get a colormap mapping pixel values to colors. Use this to construct a color bar for a
dataset.
parameters:
- in: query
schema: ColormapOptionSchema
responses:
200:
description: Array containing data values and RGBA tuples
schema: ColormapSchema
400:
description: Query parameters are invalid
"""
from terracotta.handlers.colormap import colormap
input_schema = ColormapOptionSchema()
options = input_schema.load(request.args)
payload = {'colormap': colormap(**options)}
schema = ColormapSchema()
return jsonify(schema.load(payload))
def test_colormap_handler():
from terracotta.handlers import colormap
cmap = colormap.colormap(colormap='jet', stretch_range=[0., 1.], num_values=50)
assert cmap
assert len(cmap) == 50
assert len(cmap[0]['rgba']) == 4
assert cmap[0]['value'] == 0. and cmap[-1]['value'] == 1.
def test_colormap_consistency(use_testdb, testdb, raster_file_xyz,
stretch_range, cmap_name):
"""Test consistency between /colormap and images returned by /singleband"""
import terracotta
from terracotta.xyz import get_tile_data
from terracotta.handlers import singleband, colormap
ds_keys = ['val21', 'x', 'val22']
# get image with applied stretch and colormap
raw_img = singleband.singleband(ds_keys,
raster_file_xyz,
stretch_range=stretch_range,
colormap=cmap_name)
img_data = np.asarray(Image.open(raw_img).convert('RGBA'))
# get raw data to compare to
driver = terracotta.get_driver(testdb)
with driver.connect():
tile_data = get_tile_data(driver,
ds_keys,
tile_xyz=raster_file_xyz,
tile_size=img_data.shape[:2])
# make sure all pixel values are included in colormap
num_values = stretch_range[1] - stretch_range[0] + 1
# get colormap for given stretch
cmap = colormap.colormap(colormap=cmap_name,
stretch_range=stretch_range,
num_values=num_values)
cmap = dict(row.values() for row in cmap)
# test nodata
nodata_mask = tile_data.mask
assert np.all(img_data[nodata_mask, -1] == 0)
# test clipping
below_mask = tile_data < stretch_range[0]
assert np.all(img_data[below_mask
& ~nodata_mask, :-1] == cmap[stretch_range[0]][:-1])
above_mask = tile_data > stretch_range[1]
assert np.all(img_data[above_mask
& ~nodata_mask, :-1] == cmap[stretch_range[1]][:-1])
# test values inside stretch_range
values_to_test = np.unique(tile_data.compressed())
values_to_test = values_to_test[(values_to_test >= stretch_range[0])
& (values_to_test <= stretch_range[1])]
for val in values_to_test:
rgba = cmap[val]
assert np.all(img_data[tile_data == val] == rgba)
def test_colormap_range(stretch_range):
"""Ensure that all colors from colormap file are present in returned data"""
from terracotta.cmaps import get_cmap
from terracotta.handlers import colormap
cmap_name = 'jet'
cmap_in = get_cmap(cmap_name)
num_values = cmap_in.shape[0]
cmap_out = colormap.colormap(colormap=cmap_name, stretch_range=stretch_range,
num_values=num_values)
cmap_out_arr = np.array([val['rgba'] for val in cmap_out], dtype=cmap_in.dtype)
np.testing.assert_array_equal(cmap_in, cmap_out_arr)