Processing Feedback Evaluations (paper) with OCR, Logic Apps, Azure Functions & Power BI

This is a guest blog post from Sandro Pereira - Azure & Visio MVP @ DevScope

For years, paper forms have been the preferred way for people, enterprises and event organizers to collect data in the office, in the field or in events. Although we are entering a Paperless era, in which the use of paper is progressively being eliminated, there are several situations in which the use of paper is still the best option. Either because it is still a requirement or obligation (by legal documents) or just cheaper and more practical.

One of these scenarios is found at Events Feedback Evaluations forms and, although it is quite simple and quick to create this kind of forms using, for example, Microsoft Forms or alternatively services like SurveyMonkey, let us be honest and analyze the facts:

  • Internet access at events is usually very poor or limited and despite almost all our mobile devices have data access, if we are outside our country, data roaming it is still quite expensive;
  • Alternatively, we can send/receive an email later to evaluate the event but more likely most of the attendees will ignore it and we will end up receiving little or no feedback at all.

So, at least in my opinion, paper is still one of the best options to perform Evaluations forms and so I did in the last event I organized: Oporto Global Integration Bootcamp inserted in the Global Integration Bootcamp initiative created by the Microsoft Community and supported by Microsoft.

The main problem in having Evaluations forms in physical paper is: How can we easily convert paper in data to generate additional value? How can we perform operations on it and easily gain insights?

There are plenty of OCR solutions/software’s in the market - most of them are still very expensive - that can easily scan the documents from different devices and process them using algorithms to analyze and extract the data with high confidence. Some even allow the users to manually review the extracted data from the documents before they are integrated into different information systems that normally tend to be the file system or databases.

However, neither of them is prepared to connect and integrate with all of the new technologies/data analysis platforms that appear at today's frantic pace, like Power BI. Some of these products also allow you to “easily” extend the product to connect to another system through their custom extensibility model systems but that normally means costs and time to develop some additional connector.

In order to solve this problem for the Oporto Global Integration Bootcamp event, in which I wanted to have the evaluations forms to be processed in real-time, i.e., as the attendees handed in the forms, the results were presented in a public Power BI dashboard in a matter of seconds. For this task, I chose to use:

  • DevScope SmartDocumentor OCR that, not also allowed me to extracted the data from my documents and easily integrate with other systems, but also to intelligently set my OCR streams (flows), defining:
    • Different receive locations, like FTP, file or directly from scanner devices;
    • Create/test my recognition templates and review/ validate the data which is gathered;
    • But also, enabled me to connect and send the metadata, XML or JSON, through any kind of HTTP service, I could even extend it by using a PowerShell provider that would enable me to execute a PowerShell script.
  • Azure Logic Apps that provided a way a very simplify and fast way to implement scalable integrations workflows in the cloud with an uncountednumber of connectors across the cloud and on-premises, the list is growing day by day, that will allow me to quickly integrate across services and protocols;
  • Azure Functions to run custom snippets of C# to support Logic Apps flow and perform advanced JSON to JSON transformations;
  • And finally, Power BI to create interactive data visualization (dashboards and reports)

The solution

SmartDocumentor: to process and extract metadata from paper

Well, I am not going to explain in details how the solution is implemented inside DevScope’s SmartDocumentor for it is not the point of this article, and if you want to know more about it, you can always contact me. However, let me contextualize you:

  • SmartDocumentor OCR flow will be listening in two receive locations: Share Folder and directly from the scanner device. We can specify if we want to review the documents but in this case, we will be skipping this step to allow you… yes you, the reader, to test this implementation.
  • After receiving and extract the data from the documents (paper), SmartDocumentor will send the metadata to a Logic App HTTP endpoint.

Power BI to deliver interactive data visualization (dashboards and reports)

Regarding Power BI, Logic Apps Power BI connector only accepts you to use streaming datasets (this has advantages and some disadvantages that we will see further on), that allows you to easily build real-time dashboards by pushing data into the REST API endpoint. To create your streaming datasets, you should access to Power BI with your account:

  • Select your 'Workspace à Datasets', and then on the top right corner click '+ Create' and then 'Streaming dataset'
  • In the 'New streaming dataset', select 'API' and then click 'Next'
  • In the second 'New streaming dataset', give a name to your dataset: “FeedbackForm” and then add the following elements:
    • SpeakerName (Text) – represents the name of the speaker that is obtained in the evaluation form according to the session.
    • ContentMatureFB (Number) – a value between 1 and 9 that is obtained in the evaluation form
    • GoodCommunicatorFB (Number) – a value between 1 and 9 that is obtained in the evaluation form
    • EnjoySessionFB (Number) – a value between 1 and 9 that is obtained in the evaluation form
    • MetExpectationsFB (Number) – a value between 1 and 9 that is obtained in the evaluation form
    • SpeakerAvrg (Number) – A simple average calculation (sum all the above metrics divide by 4)
    • WhoAmI (Text) – represents the type of attendee you are (developer, architect, …) that is obtained in the evaluation form
    • SpeakerPicture (Text) – picture of the speaker according to the session that is that is obtained in the evaluation form.
  • And because we want to create interactive reports in order to have more insights from the event. We need to enable 'Historic data analysis' and then click 'Create'

Unfortunately, streaming dataset is meant to be used for real-time streaming and is a little limited in terms of want we can do with it. For example, it doesn’t allow you to combine different sources, for example, a “table” that can correlate speaker to get their pictures, or to make aggregations of metrics like “Speaker average”. Which means that we need to send all of this information from Logic Apps.

Azure Function to apply JSON transformations (Content Enricher, Content Filter & Name-Value Transformation Patterns)

To solve and bypass these streaming dataset limitations we use an Azure Function inside Logic App that not only transforms the JSON message received from SmartDocumentor with the Evaluation metadata but also add missing information - Content Enricher Pattern. It is very common when we want to exchange messages between different systems or applications, that the target system requires more information than the source system can provide. In this case, the source system (paper) will not send the Name of the speaker, the speaker average metric and the picture of the speaker, but our target system (Power BI) expects that information.

But also, to apply a transformation pattern - Content Filter - that not only removes unnecessarily data elements but it is also used to simplify the structure of the message, i.e., 'flattens' the hierarchy into a simple list of elements that can be more easily understood and processed by other systems.

And finally transform a name–value pair (NVP), key–value pair (KVP), field–value pair, attribute–value pair or even Entity-Attribute-Value model (EAV) data representation that is widely used into a to more Hierarchical Schema.

To do that we create a “GenericWebHook-CSharp” function that accepts the NVP JSON message, which was originally sent by OCR, and generate a friendlier message.


#r "Newtonsoft.Json"

using System;
using System.Net;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;

public static async Task<object> Run(HttpRequestMessage req, TraceWriter log)
 log.Info($"Webhook was triggered!");

 string jsonContent = await req.Content.ReadAsStringAsync();
 dynamic data = JsonConvert.DeserializeObject(jsonContent);

 string speakerName = string.Empty;
 string speakerPicture = string.Empty;
 int pos = 0;
 for (int i = 5; i <= 8; i++)
 if (!String.IsNullOrEmpty(data[i]["Value"].Value))
 pos = i;

 switch (pos)
 case 5:
 speakerName = "Ricardo Torre";
 speakerPicture = "";
 case 6:
 speakerName = "José António Silva e Pedro Sousa";
 speakerPicture = "";
 case 7:
 speakerName = "João Ferreira";
 speakerPicture = "";
 case 8:
 speakerName = "Sandro Pereira";
 speakerPicture = "";
 speakerName = "Unknown";
 speakerPicture = "";

 int result = 0;
 decimal avrg = (decimal)((int.TryParse(data[9]["Value"].Value, out result) ? result : 0) + (int.TryParse(data[10]["Value"].Value, out result) ? result : 0) + (int.TryParse(data[11]["Value"].Value, out result) ? result : 0) + (int.TryParse(data[12]["Value"].Value, out result) ? result : 0)) / 4;

 JObject eval =
 new JObject(
 new JProperty("SpeakerName", speakerName),
 new JProperty("SpeakerPicture", speakerPicture),
 new JProperty("ContentMatureFB", data[9]["Value"].Value),
 new JProperty("GoodCommunicatorFB", data[10]["Value"].Value),
 new JProperty("EnjoySessionFB", data[11]["Value"].Value),
 new JProperty("MetExpectationsFB", data[12]["Value"].Value),
 new JProperty("SpeakerAvrg", avrg),
 new JProperty("WhoAmI", data[30]["Value"].Value));

 log.Info($"Webhook was Complete!");

 return req.CreateResponse(HttpStatusCode.OK, new
 MsgEval = eval

Notice that for example in the following transformation rule:

speakerName = "Sandro Pereira";

speakerPicture = "";

We are transforming the selected session in the Evaluation form to the name of the speaker and his picture. Why the picture URL? Well, as mentioned before, Power BI streaming dataset has some limitation in what we can do by default. So, in order for us to be able to present the speaker picture in the Power BI report and/or dashboard, we are forced to send a public picture URL (in this case it is stored in my blog) as an input of our dataset.

For the same reason, because we cannot make a new measure derived from the others when using streaming dataset, instead we need to send it as an input of our dataset and in order for us to calculate the average performance of a speaker, we will be using this basic formula:

decimal avrg = (decimal)((int.TryParse(data[9]["Value"].Value, out result) ? result : 0) + (int.TryParse(data[10]["Value"].Value, out result) ? result : 0) + (int.TryParse(data[11]["Value"].Value, out result) ? result : 0) + (int.TryParse(data[12]["Value"].Value, out result) ? result : 0)) / 4;

The output of the function will be a JSON message.

Logic Apps to create an integration process flow

The missing piece: Logic App! The tool that allows us to transform a product (OCR software) that in principle seemed closed and limited in terms of features into a product without frontiers/fences. I know that normally these type of products (OCR) have extensibility model systems that allow you to extend the product with your personal requirements, but that normally means you need to have developer skills and probably will cost you time and money, something we want to avoid.

The beauty of using Logic App is that provides us a very simplify, robust, scalable, not expensive and fast way to extend the capabilities of my OCR software and integrate with an uncounted number of Cloud and on-premises applications or/and systems.

In order to integrate SmartDocumentor OCR with Power BI, we need to create a Logic App that:

  • Accept a JSON through an HTTP Post. For that, we use a 'Request / Response – Manual' trigger. And in this case, because we don’t need to have friendly tokens to access the elements of the message, we don’t specify a JSON Schema.
  • Call an Azure Function to transform the original OCR JSON to the expected JSON message to send to Power BI. For that, we use an 'Azure Functions' action, specifying the function that we created previously.
  • After that, we use a 'Parse JSON' action, only to allow us to parse JSON content into friendly tokens (something like a quick alias to the fields) for being easily consumed in other action of the process.
  • In the last step of the Logic App: we push the data into the Power BI streaming dataset created earlier by using the new 'Power BI' Connector. To do this we need to:
    • Add a '+New step', 'Add an action', and then enter 'Power BI' into the search box. Select “Add row to streaming dataset” from the actions list.
    • Select the name of the workspace and then the name of the streaming dataset
    • The next step is to select the Table titled “RealTimeData”
    • And finally, map the input data fields with the friendly tokens generated in the 'Parse JSON' action

The end result

After saving the Logic App and process the Evaluation forms, the result is this beautiful and interactive report that we can present in a monitor during the breaks of our events:

What do we need to do to extend the process for archiving the messages? Simple, just edit and change the Logic App by adding, for example, a Dropbox, OneDrive or File Connector into your process and save it! It is that easy!

How can you test the solution?

You can try part of this solution because, unfortunately, we cannot submit the paper via web… yet… yet 😊. So, in this case let us assume that we already have the paper digitalized/scanned and we only want to try the OCR and integration process.

To try the solution, you need to:


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