如何以灰度转换造型瓷砖（2022）
我正在尝试将地形数据显示为背景，以将一些我最上面的洪水数据放置。我想以一定的颜色尺度（灰色似乎很受欢迎）以避免在洪水栏中避免使用这种颜色，以避免混淆。
我正在使用Cartopy的img_tiles，实际上已经提出了同样的问题（如何转换格雷斯尺度中的摄影瓷砖？）。但是现在，解决方案（添加CMAP =“ ...”）似乎在较新版本的Cartopy上不再起作用。尝试“ cmap”时，我有以下错误： error 。那么，是否有一种将图像转换为灰度绘制的方法？
我拥有的代码如下：
import matplotlib.pyplot as plt
import cartopy.crs as ccrs
import cartopy.io.img_tiles as cimgt
fig = plt.figure(figsize=(10,7.5))
ax = plt.axes(projection=ccrs.PlateCarree())
[lon0,lat0,lon1,lat1] = [102., 11., 107., 15.]
ax.set_extent([lon0, lon1, lat0, lat1])
stamen_terrain = cimgt.Stamen(desired_tile_form="L", style="terrain-background")
ax.add_image(stamen_terrain, 8, cmap='gray')
如果没有cmap ='灰色'，代码可行，但它会给我固定的颜色： 默认颜色
edit 1：我对ShadereliefeSri也有同样的问题从我如何获取地形数据，但从我的显示方式（ax）的创建方式或函数ax.Add_image（）工作方式来看。当我添加cmap时，结果是相同的。代码如下：
from cartopy.io.img_tiles import GoogleTiles
class ShadedReliefESRI(GoogleTiles):
# shaded relief
def _image_url(self, tile):
x, y, z = tile
url = ('https://server.arcgisonline.com/ArcGIS/rest/services/' \
'World_Shaded_Relief/MapServer/tile/{z}/{y}/{x}.jpg').format(
z=z, y=y, x=x)
return url
ax.add_image(ShadedReliefESRI(), 8, cmap ='gray')
编辑2：试图用Spyder绘制，有趣的东西仍然显示出来，看起来不错，但是出现了错误，并且可以防止我使用savefig（）。
I'm trying to display topography data as a background to put some flooding data I have on top. And I want to display this topography in a certain color scale (gray seems to be popular) to avoid having that color in my color bar for the flooding data to avoid confusion.
I'm using Cartopy's img_tiles, and this same problem has actually been asked 4 years ago (How to convert Cartopy tiles in grayscale?). But now the solution (adding cmap="...") doesn't seem to work anymore on the newer version of Cartopy. I have the following error while trying "cmap":
error. So, is there a different way to convert the image into a gray scale for plotting?
The code I have is as follow:
import matplotlib.pyplot as plt
import cartopy.crs as ccrs
import cartopy.io.img_tiles as cimgt
fig = plt.figure(figsize=(10,7.5))
ax = plt.axes(projection=ccrs.PlateCarree())
[lon0,lat0,lon1,lat1] = [102., 11., 107., 15.]
ax.set_extent([lon0, lon1, lat0, lat1])
stamen_terrain = cimgt.Stamen(desired_tile_form="L", style="terrain-background")
ax.add_image(stamen_terrain, 8, cmap='gray')
Without cmap='gray', the code works, but it will give me a fixed color:
default color
Edit 1: I have the same problem with ShadeReliefESRI, seems like the problem is not coming from how I acquire the topography data but from how I display it, either with how the axis (ax) was created or how the function ax.add_image() work. The result is the same when I add cmap. Codes are as below:
from cartopy.io.img_tiles import GoogleTiles
class ShadedReliefESRI(GoogleTiles):
# shaded relief
def _image_url(self, tile):
x, y, z = tile
url = ('https://server.arcgisonline.com/ArcGIS/rest/services/' \
'World_Shaded_Relief/MapServer/tile/{z}/{y}/{x}.jpg').format(
z=z, y=y, x=x)
return url
ax.add_image(ShadedReliefESRI(), 8, cmap ='gray')
Edit 2: Trying to plot with Spyder, funny thing, the figure still show up, looking good, but the error also appears and it prevents me from using savefig().
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我没有运行您的代码的预选。我使用CATTOPY版本0.19.0.post1。
如果您更喜欢B/W图像对于背景，则可以从 ref 。例如，使用此代码段，
您可以获取此图：
I have no proplem running your code. I use cartopy version 0.19.0.post1.
If you prefer B/W image for the background, the "toner" maps are available to choose from ref. For example, with this code snippet
you can get this plot: