来自谷歌硬盘的背景图像

Question

我正在创建一个GoogleColab，在图像上显示一些热图的数据。我一直在使用类似于plotly website中的代码

它可以很好地处理来自网站的链接，但是当尝试使用Google Drive链接时，它不起作用。我正在使用以下格式的链接：https://docs.google.com/uc?export=download&id=<file-id> 在标记字段中使用图像时，图像显示良好，但不是通过绘图

代码示例：

fig = px.density_heatmap(df, x="x", y="y",
                         color_continuous_scale = [(0, "rgba(0, 255, 0, 0)"), 
                                                   (0.5, "rgba(0, 255, 0, 0.5)"), 
                                                   (1, "rgba(0, 255, 0, 1)")],
                         height=810, width=1440)
fig.add_layout_image(
        dict(
            source="https://docs.google.com/uc?export=download&id=1JEyyYCse6sWM3yMUwDG2l7XzaGxej-VZ",
            xref="x",
            yref="y",
            x=0,
            y=0,
            sizex=1920,
            sizey=1080,
            sizing="stretch",
            opacity=1,
            layer="below")
)
fig.update_layout(template="plotly_white")
fig.show()

有没有办法解决这个问题，或者仅仅是图书馆没有考虑到这个问题

编辑：我想使用一个不公开的谷歌硬盘链接，希望我能使用谷歌Colab认证。找到了here的可能答案

Answer 1

提示您下载图像的URL。如plotly documentation中所述，您需要图像的URL或PIL图像对象

A background image can be added to the layout of a figure with fig.add_layout_image or by setting the images parameter of go.Layout. The source attribute of a go.layout.Image can be the URL of an image, or a PIL Image object (from PIL import Image; img = Image.open('filename.png')).

也就是说，您可以下载图像并将其作为PIL图像对象读取到python中，然后将其用作背景

见下面的例子；由于您尚未共享数据，我将使用plotly网页上的示例数据集

import requests
from PIL import Image
import plotly.graph_objects as go

下载iamge

## function to dowload google drive image taken from https://stackoverflow.com/a/39225272/6461462
def download_file_from_google_drive(id, destination):
    URL = "https://docs.google.com/uc?export=download"

    session = requests.Session()

    response = session.get(URL, params = { 'id' : id }, stream = True)
    token = get_confirm_token(response)

    if token:
        params = { 'id' : id, 'confirm' : token }
        response = session.get(URL, params = params, stream = True)

    save_response_content(response, destination)    

def get_confirm_token(response):
    for key, value in response.cookies.items():
        if key.startswith('download_warning'):
            return value

    return None

def save_response_content(response, destination):
    CHUNK_SIZE = 32768

    with open(destination, "wb") as f:
        for chunk in response.iter_content(CHUNK_SIZE):
            if chunk: ## filter out keep-alive new chunks
                f.write(chunk)

if __name__ == "__main__":
    file_id = 'TAKE ID FROM SHAREABLE LINK'
    destination = 'DESTINATION FILE ON YOUR DISK'
    download_file_from_google_drive(file_id, destination)
    
## download the image
download_file_from_google_drive("1JEyyYCse6sWM3yMUwDG2l7XzaGxej-VZ", "D:\\test\\gdrive.png")

图表

## read the image into python as a PIL Image object
img = Image.open("D:\\test\\gdrive.png")


## Create figure
fig = go.Figure()

## Add trace
fig.add_trace(
    go.Scatter(x=[0, 0.5, 1, 2, 2.2], y=[1.23, 2.5, 0.42, 3, 1])
)

## Add images
fig.add_layout_image(
        dict(
            source=img,
            xref="x",
            yref="y",
            x=0,
            y=3,
            sizex=3,
            sizey=3,
            sizing="stretch",
            opacity=0.5,
            layer="below")
)

## Set templates
fig.update_layout(template="plotly_white")

fig.show()