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Output Document Is Blurry after Saving Presentation to HTML

We have a problem with PowerPoint files, when converting a PPTM file to HTLM the content becomes very blurry.

I am providing you with the original file as an attachment as well as the files after processing.
The processing was carried out with Aspose.Slides for .NET 21.3.0

Can you watch what’s wrong?

cordiallyBUG_00005.zip (2.3 MB)

Thank you for the issue description. I reproduced the problem and received the same results. I’ve logged the issue in our tracking system with ID SLIDESNET-42536. Our development team will investigate this case. You will be notified when it is fixed.

Our development team investigated the issue. Aspose.Slides saves the smallest output HTML document by default with 72dpi and deleted cropped areas. For better quality, you can use the HtmlOptions.PicturesCompression and set it to PicturesCompression.Dpi96 or higher as shown below:

HtmlOptions htmlOptions = new HtmlOptions
    PicturesCompression = PicturesCompression.Dpi96
presentation.Save("outputDocument_dpi96.html", SaveFormat.Html, htmlOptions);

If you need full-quality images, please use the HtmlOptions.DeletePicturesCroppedAreas property:

HtmlOptions htmlOptions = new HtmlOptions
    DeletePicturesCroppedAreas = false
presentation.Save("outputDocument_noCrop.html", SaveFormat.Html, htmlOptions);

Documents: Convert Powerpoint PPT and PPTX to HTML
API Reference: HtmlOptions Class

Note: Starting from version 21.8, images will be rendered at the highest quality if the DeletePictureCroppedAreas = false option is specified.

The issues you have found earlier (filed as SLIDESNET-42536) have been fixed in this update.


I confirm that this issue as been resolved by version 21.10



With the correction you provided the images are less blurry, however they remain blurry.

The example provided shows it clearly,

  • Saving the PPTM file in PPTX => the rendering is correct
  • Saving the PPTM file in PDF => the rendering is blurry
  • Saving the PPTM file in HTML => the rendering is blurry
    Can you look ?

Thank you Best regards

element.zip (492.4 KB)

You can increase the image quality in output HTML by using PicturesCompression property as shown below:

var htmlOptions = new HtmlOptions
    PicturesCompression = PicturesCompression.Dpi330,
    DeletePicturesCroppedAreas = false

presentation.Save("outputDocument.html", SaveFormat.Html, htmlOptions);

As far as PDF export is concerned, you should use SufficientResolution property like this:

var pdfOptions = new PdfOptions
    SufficientResolution = 320,

presentation.Save("outputDocument_out.pdf", SaveFormat.Pdf, pdfOptions);

API Reference: PdfOptions Class