如何吸取一张图片的色值？

import image from "@ohos.multimedia.image"; 
import { effectKit } from "@kit.ArkGraphics2D"; 
import { resourceManager } from '@kit.LocalizationKit'; 
 
@Entry 
@Component 
struct Index { 
  async aboutToAppear(): Promise<void> { 
 
    const context: Context = getContext(this); 
    // 获取resourceManager资源管理 
    const resourceMgr: resourceManager.ResourceManager = context.resourceManager; 
    const fileData: Uint8Array = await resourceMgr.getRawFileContent('startIcon.png'); 
    // 获取图片的ArrayBuffer 
    const buffer = fileData.buffer as ArrayBufferLike; 
    const imageSource: image.ImageSource = image.createImageSource(buffer.slice(0, buffer.byteLength)); 
    const pixelMap1: image.PixelMap = await imageSource.createPixelMap(); 
 
    effectKit.createColorPicker(pixelMap1, (error, colorPicker) => { 
      if (error) { 
        console.error('Failed to create color picker.'); 
      } else { 
        console.info('Succeeded in creating color picker.'); 
        colorPicker.getMainColor().then(color => { 
          console.info('Succeeded in getting main color.'); 
          console.info(`color[ARGB]=${color.alpha},${color.red},${color.green},${color.blue}`); 
        }) 
      } 
    }) 
 
  } 
 
  build() { 
    Text('hello') 
  } 
}