谷歌广告图片资产分析中geom_image显示填充图形而非图片的问题

问题原因 #

你的代码中，全局ggplot()的aes()里设置了fill和colour映射，而geom_image()默认会继承这些全局美学属性，导致图片被填充颜色覆盖，无法显示原本的图片内容。

解决方案 #

在geom_image()中添加inherit.aes = FALSE参数，切断对全局美学映射的继承，仅保留该图层需要的x、y、image映射即可：

# Packages
library(tidyverse)
library(ggimage)
library(ggchicklet)

# Create sample data
df <- data.frame(
  Asset = c("running_wide", "biomechanicsMan_wide", "running_square", "mandelbrot_wide", 
            "mandelbrot_square", "lines_wide", "systems_square", "systems_wide", "lines_square"),
  status = rep("Enabled", 9),
  Asset_type = c("Image", "Image", "Square image", "Image", "Square image", "Image", "Square image", "Image", "Square image"),
  Performance = c("Best", "Best", "Best", "Best", "Low", "Best", "Good", "Best", "Good"),
  Asset_source = rep("Advertiser", 9),
  val = rep(10, 9),
  font_size = c(10, 10, 10, 10, 10, 10, 10, 10, 10),
  asset_name = rep("ball", 9),
  path = rep("https://upload.wikimedia.org/wikipedia/commons/thumb/7/7a/Basketball.png/220px-Basketball.png", 9)
)

ggplot(df, aes(x = reorder(Asset, font_size), y = val, fill = Performance, colour = Performance)) + 
  geom_chicklet(width = 0.9, alpha = 0.3, size = 1) + 
  scale_fill_manual(values = c("Best" = "#D6AF36", 
                               "Good" = "#A7A7AD",
                               "Low" = "#A77044"), name = NULL) + 
  scale_colour_manual(values = c("Best" = "#D6AF36", 
                                 "Good" = "#A7A7AD",
                                 "Low" = "#A77044"), name = NULL) +   
  # 关键修改：添加inherit.aes = FALSE
  geom_image(aes(x = reorder(Asset, font_size), y = 1, image = path), 
             size = 0.08, inherit.aes = FALSE) +
  coord_flip() +
  theme_void() + 
  theme(
    legend.title = element_text(size = 16),
    legend.text=element_text(size=13)
  )

原理说明 #

geom_image()本身不需要fill和colour这类美学属性，当它继承了全局的这些映射后，会将图片渲染为填充几何图形而非原始图片。通过inherit.aes = FALSE可以让该图层仅使用自身定义的美学映射，从而正常显示图片。

内容的提问来源于stack exchange，提问作者JDiddy36