compressImage

<style>.img{ display:block; max-width: 100%; margin: 20px auto;}</style>
<h1>点击按钮选择图片</h1>
<button id="J_chooseImage" class="btn">选择图片</button>
压缩前：
<img id="J_imageViewer" class="img" />
压缩后：
<img id="J_compressedImage" class="img" />

<script type="text/javascript">
function ready(callback) {
  // 如果jsbridge已经注入则直接调用
  if (window.AlipayJSBridge) {
    callback && callback();
  } else {
    // 如果没有注入则监听注入的事件
    document.addEventListener('AlipayJSBridgeReady', callback, false);
  }
}
ready(function() {
  var btn = document.querySelector('#J_chooseImage');

  btn.addEventListener('click', function(e) {
    AlipayJSBridge.call(
      'chooseImage',
      { count: 1, publicDomain: true },
      function (result) {
        alert(JSON.stringify(result));

        var apFilePath = result.apFilePathsV2 || result.apFilePaths || [];
        if (typeof apFilePath === 'string') {
          try {
            apFilePath = JSON.parse(apFilePath);
          } catch (e) {}
        }

        if (apFilePath.length && /^https?:/.test(apFilePath[0])) {
          document.querySelector('#J_imageViewer').src = apFilePath[0];

          AlipayJSBridge.call('compressImage', {
            apFilePaths: apFilePath, 
            compressLevel: 0
          }, function(result) {
            document.querySelector('#J_compressedImage').src = result.apFilePaths[0];
          });
        }
      }
    );
  }, false);
});
</script>