科尔多瓦插件相机捕获灰度图像

Question

我正在使用Cordova-plugin-camera捕获图像并获取base64图像。我能知道是否有捕获灰度图像的任何方法，或者如何将其转换为灰度图像。

$scope.captureSlipImage = function () {

    // capture photo
    navigator.camera.getPicture(onSuccess, onFail, {
        quality: 50,
        destinationType: Camera.DestinationType.DATA_URL,
        encodingType: Camera.EncodingType.JPEG,
        targetWidth: 400,
        saveToPhotoAlbum: false,
        correctOrientation: true,
        pictureSourceType: Camera.PictureSourceType.CAMERA
    });

    function onSuccess(imageData) {
    
        $scope.captureData.capturedImage = "data:image/jpeg;base64," + imageData;
      
    function onFail(message) {
        alert('Failed because: ' + message);
    }

};