import io import numpy as np from numpy.testing import assert_array_almost_equal import pytest from matplotlib import ( collections, path, pyplot as plt, transforms as mtransforms, rcParams) from matplotlib.image import imread from matplotlib.backends.backend_agg import FigureCanvasAgg as FigureCanvas from matplotlib.figure import Figure from matplotlib.testing.decorators import image_comparison def test_repeated_save_with_alpha(): # We want an image which has a background color of bluish green, with an # alpha of 0.25. fig = Figure([1, 0.4]) canvas = FigureCanvas(fig) fig.set_facecolor((0, 1, 0.4)) fig.patch.set_alpha(0.25) # The target color is fig.patch.get_facecolor() buf = io.BytesIO() fig.savefig(buf, facecolor=fig.get_facecolor(), edgecolor='none') # Save the figure again to check that the # colors don't bleed from the previous renderer. buf.seek(0) fig.savefig(buf, facecolor=fig.get_facecolor(), edgecolor='none') # Check the first pixel has the desired color & alpha # (approx: 0, 1.0, 0.4, 0.25) buf.seek(0) assert_array_almost_equal(tuple(imread(buf)[0, 0]), (0.0, 1.0, 0.4, 0.250), decimal=3) def test_large_single_path_collection(): buff = io.BytesIO() # Generates a too-large single path in a path collection that # would cause a segfault if the draw_markers optimization is # applied. f, ax = plt.subplots() collection = collections.PathCollection( [path.Path([[-10, 5], [10, 5], [10, -5], [-10, -5], [-10, 5]])]) ax.add_artist(collection) ax.set_xlim(10**-3, 1) plt.savefig(buff) def test_marker_with_nan(): # This creates a marker with nans in it, which was segfaulting the # Agg backend (see #3722) fig, ax = plt.subplots(1) steps = 1000 data = np.arange(steps) ax.semilogx(data) ax.fill_between(data, data*0.8, data*1.2) buf = io.BytesIO() fig.savefig(buf, format='png') def test_long_path(): buff = io.BytesIO() fig, ax = plt.subplots() np.random.seed(0) points = np.random.rand(70000) ax.plot(points) fig.savefig(buff, format='png') @image_comparison(baseline_images=['agg_filter'], extensions=['png'], remove_text=True) def test_agg_filter(): def smooth1d(x, window_len): s = np.r_[2*x[0] - x[window_len:1:-1], x, 2*x[-1] - x[-1:-window_len:-1]] w = np.hanning(window_len) y = np.convolve(w/w.sum(), s, mode='same') return y[window_len-1:-window_len+1] def smooth2d(A, sigma=3): window_len = max(int(sigma), 3)*2 + 1 A1 = np.array([smooth1d(x, window_len) for x in np.asarray(A)]) A2 = np.transpose(A1) A3 = np.array([smooth1d(x, window_len) for x in A2]) A4 = np.transpose(A3) return A4 class BaseFilter(object): def prepare_image(self, src_image, dpi, pad): ny, nx, depth = src_image.shape padded_src = np.zeros([pad*2 + ny, pad*2 + nx, depth], dtype="d") padded_src[pad:-pad, pad:-pad, :] = src_image[:, :, :] return padded_src # , tgt_image def get_pad(self, dpi): return 0 def __call__(self, im, dpi): pad = self.get_pad(dpi) padded_src = self.prepare_image(im, dpi, pad) tgt_image = self.process_image(padded_src, dpi) return tgt_image, -pad, -pad class OffsetFilter(BaseFilter): def __init__(self, offsets=None): if offsets is None: self.offsets = (0, 0) else: self.offsets = offsets def get_pad(self, dpi): return int(max(*self.offsets)/72.*dpi) def process_image(self, padded_src, dpi): ox, oy = self.offsets a1 = np.roll(padded_src, int(ox/72.*dpi), axis=1) a2 = np.roll(a1, -int(oy/72.*dpi), axis=0) return a2 class GaussianFilter(BaseFilter): "simple gauss filter" def __init__(self, sigma, alpha=0.5, color=None): self.sigma = sigma self.alpha = alpha if color is None: self.color = (0, 0, 0) else: self.color = color def get_pad(self, dpi): return int(self.sigma*3/72.*dpi) def process_image(self, padded_src, dpi): tgt_image = np.zeros_like(padded_src) aa = smooth2d(padded_src[:, :, -1]*self.alpha, self.sigma/72.*dpi) tgt_image[:, :, -1] = aa tgt_image[:, :, :-1] = self.color return tgt_image class DropShadowFilter(BaseFilter): def __init__(self, sigma, alpha=0.3, color=None, offsets=None): self.gauss_filter = GaussianFilter(sigma, alpha, color) self.offset_filter = OffsetFilter(offsets) def get_pad(self, dpi): return max(self.gauss_filter.get_pad(dpi), self.offset_filter.get_pad(dpi)) def process_image(self, padded_src, dpi): t1 = self.gauss_filter.process_image(padded_src, dpi) t2 = self.offset_filter.process_image(t1, dpi) return t2 fig = plt.figure() ax = fig.add_subplot(111) # draw lines l1, = ax.plot([0.1, 0.5, 0.9], [0.1, 0.9, 0.5], "bo-", mec="b", mfc="w", lw=5, mew=3, ms=10, label="Line 1") l2, = ax.plot([0.1, 0.5, 0.9], [0.5, 0.2, 0.7], "ro-", mec="r", mfc="w", lw=5, mew=3, ms=10, label="Line 1") gauss = DropShadowFilter(4) for l in [l1, l2]: # draw shadows with same lines with slight offset. xx = l.get_xdata() yy = l.get_ydata() shadow, = ax.plot(xx, yy) shadow.update_from(l) # offset transform ot = mtransforms.offset_copy(l.get_transform(), ax.figure, x=4.0, y=-6.0, units='points') shadow.set_transform(ot) # adjust zorder of the shadow lines so that it is drawn below the # original lines shadow.set_zorder(l.get_zorder() - 0.5) shadow.set_agg_filter(gauss) shadow.set_rasterized(True) # to support mixed-mode renderers ax.set_xlim(0., 1.) ax.set_ylim(0., 1.) ax.xaxis.set_visible(False) ax.yaxis.set_visible(False) def test_too_large_image(): fig = plt.figure(figsize=(300, 1000)) buff = io.BytesIO() with pytest.raises(ValueError): fig.savefig(buff) def test_chunksize(): x = range(200) # Test without chunksize fig, ax = plt.subplots() ax.plot(x, np.sin(x)) fig.canvas.draw() # Test with chunksize fig, ax = plt.subplots() rcParams['agg.path.chunksize'] = 105 ax.plot(x, np.sin(x)) fig.canvas.draw() @pytest.mark.backend('Agg') def test_jpeg_dpi(): Image = pytest.importorskip("PIL.Image") # Check that dpi is set correctly in jpg files. plt.plot([0, 1, 2], [0, 1, 0]) buf = io.BytesIO() plt.savefig(buf, format="jpg", dpi=200) im = Image.open(buf) assert im.info['dpi'] == (200, 200)