我想将颜色映射应用于图像，并写入结果图像，而不使用轴、标签、标题或matplotlib自动添加的任何内容。以下是我所做的:
def make_image(inputname,outputname):
data = mpimg.imread(inputname)[:,:,0]
fig = plt.imshow(data)
fig.set_cmap('hot')
fig.axes.get_xaxis().set_visible(False)
fig.axes.get_yaxis().set_visible(False)
plt.savefig(outputname)
它成功地删除了图形的轴，但保存的图形显示了一个白色填充，以及实际图像周围的框架。
我如何删除它们(至少是白色填充)?
当前回答
这将删除所有的填充和边框:
from matplotlib import pyplot as plt
fig = plt.figure()
fig.patch.set_visible(False)
ax = fig.add_subplot(111)
plt.axis('off')
plt.imshow(data)
extent = ax.get_window_extent().transformed(fig.dpi_scale_trans.inverted())
plt.savefig("../images/test.png", bbox_inches=extent)
其他回答
首先，对于某些图像格式(例如TIFF)，你可以在标题中保存颜色图，大多数查看器会显示你的数据和颜色图。
为了保存实际的matplotlib图像，这对于向图像添加注释或其他数据非常有用，我使用了以下解决方案:
fig, ax = plt.subplots(figsize=inches)
ax.matshow(data) # or you can use also imshow
# add annotations or anything else
# The code below essentially moves your plot so that the upper
# left hand corner coincides with the upper left hand corner
# of the artist
fig.subplots_adjust(left=0, right=1, top=1, bottom=0, wspace=0, hspace=0)
# now generate a Bbox instance that is the same size as your
# single axis size (this bbox will only encompass your figure)
bbox = matplotlib.transforms.Bbox(((0, 0), inches))
# now you can save only the part of the figure with data
fig.savefig(savename, bbox_inches=bbox, **kwargs)
您还可以将图形的范围指定为bbox_inch参数。这将消除图形周围的白色填充。
def make_image(inputname,outputname):
data = mpimg.imread(inputname)[:,:,0]
fig = plt.imshow(data)
fig.set_cmap('hot')
ax = fig.gca()
ax.set_axis_off()
ax.autoscale(False)
extent = ax.get_window_extent().transformed(plt.gcf().dpi_scale_trans.inverted())
plt.savefig(outputname, bbox_inches=extent)
这将删除所有的填充和边框:
from matplotlib import pyplot as plt
fig = plt.figure()
fig.patch.set_visible(False)
ax = fig.add_subplot(111)
plt.axis('off')
plt.imshow(data)
extent = ax.get_window_extent().transformed(fig.dpi_scale_trans.inverted())
plt.savefig("../images/test.png", bbox_inches=extent)
如此:
plot.axis('off')
ax = plot.gca()
ax.get_xaxis().set_visible(False)
ax.get_yaxis().set_visible(False)
这是最后对我有用的方法:
斧子。margin (x=0, y=0, tight=True)是关键行。
fig = plt.figure(figsize=(8, 8))
ax = plt.Axes(fig, [0., 0., 1., 1.])
ax.set_axis_off()
ax.margins(x=0, y=0, tight=True)
fig.add_axes(ax)
for triangle in list_of_triangles:
x_points = [point[0] for point in triangle]
y_points = [point[1] for point in triangle]
plt.fill(x_points, y_points, 'k', edgecolor='k')
plt.savefig("test.png", bbox_inches=0, pad_inches=0)
plt.show()
