How to convert a PowerPoint PPTX into a Thumbnail PNG Image in Node.JS

Converting a PowerPoint presentation into a thumbnail is a surprisingly complex and difficult thing to do. It requires multiple format conversions, as well as slide separation and image resizing. I won’t get into all the pitfalls that can arise from all these steps. Instead I will give you a get-out-of-jail-free card in the form of an API that is custom-built for creating thumbnails from virtually any file format out there.

With npm install, let’s retrieve our client files.

npm install cloudmersive-convert-api-client --save

And now set up a simple API function call using a key:

var CloudmersiveConvertApiClient = require('cloudmersive-convert-api-client');
var defaultClient = CloudmersiveConvertApiClient.ApiClient.instance;
// Configure API key authorization: Apikey
var Apikey = defaultClient.authentications['Apikey'];
Apikey.apiKey = 'YOUR API KEY';
// Uncomment the following line to set a prefix for the API key, e.g. "Token" (defaults to null)
//Apikey.apiKeyPrefix = 'Token';
var apiInstance = new CloudmersiveConvertApiClient.ConvertDocumentApi();
var inputFile = "/path/to/file"; // File | Input file to perform the operation on.
var opts = {
'maxWidth': 56, // Number | Optional; Maximum width of the output thumbnail - final image will be as large as possible while less than or equal to this width. Default is 128.
'maxHeight': 56, // Number | Optional; Maximum height of the output thumbnail - final image will be as large as possible while less than or equal to this width. Default is 128.
'extension': "extension_example" // String | Optional; Specify the file extension of the inputFile. This will improve the response time in most cases. Also allows unsupported files without extensions to still return a corresponding generic icon.
};
var callback = function(error, data, response) {
if (error) {
console.error(error);
} else {
console.log('API called successfully. Returned data: ' + data);
}
};
apiInstance.convertDocumentAutodetectToThumbnail(inputFile, opts, callback);

And the rest is pretty self-explanatory. Run the code, get your thumbnail. Easy.