图片剪切，HarmonyOS提供图片剪切能力，并对截取后的资源进行操作。

let path = this.context.getApplicationContext().fileDirs + "test.jpg"; 
const imageSourceApi = image.createImageSource(path);

const decodingOptions = { 
  desiredSize: { 
    height:0, 
    width:0 
  }, 
  //按矩形区域裁剪 
  desiredRegion: { 
    size: { 
      height:100, 
      width:100 
    }, 
    x:0, 
    y:0 
  }, 
  //旋转90度 
  rotate:90 
} 
const imageSourceApi = image.createImageSource(buffer) 
imageSourceApi.createPixelMap(decodingOptions).then(pixelMap => { 
  this.handlePixelMap(pixelMap) 
})