Font Size Was Changed After Converting a PPT File to a PPTX File in C#

Aspose.Slides Product Family
, ,
1

I used Aspose.Slides.NET version 25.8.0 to convert this PPT file to PPTX format. The font in the output file differs from that in the original file.

Here is the code snippet that I use to convert this file:

Presentation document = new Aspose.Slides.Presentation(inputFilePath);
document.Save(outputFilePath, Aspose.Slides.Export.SaveFormat.Pptx);

Input/Output file:
input_output_files.zip (3.4 MB)

Different visual:
FontSizeDifference_PPT_vs_PPTX.png (46.1 KB)

Please help me investigate it. Thank you very much.

2

@dunghnguyen

It sounds like you’re experiencing an issue with font size discrepancies after converting a PPT file to PPTX using Aspose.Slides. This can occur due to differences in how fonts are handled between the two formats.

Cause: The issue may arise from missing fonts on the system where the conversion is taking place, leading Aspose to substitute them with different fonts, which can result in size differences.

Solution: Here are several steps to troubleshoot and resolve the issue:

  1. Check Font Availability: Ensure that the fonts used in the original PPT file are installed on the system where the conversion is taking place. If the font is not available, Aspose may substitute it with a different font.

  2. Set Font Substitution: Specify font substitution settings in Aspose.Slides to ensure the correct fonts are used during conversion. Use the FontsLoader class to load the fonts before performing the conversion. Here’s a code snippet to illustrate this:

    // Load the fonts
FontsLoader.LoadExternalFonts(new string[] { "path_to_your_fonts" });

// Convert the PPT to PPTX
Presentation document = new Aspose.Slides.Presentation(inputFilePath);
document.Save(outputFilePath, Aspose.Slides.Export.SaveFormat.Pptx);

  3. Review Slide Layouts: Check if the slide layouts in the PPT file are being preserved correctly in the PPTX output, as this can affect text rendering.

  4. Update Aspose.Slides: If you are using an older version of Aspose.Slides (like 25.8.0), consider updating to the latest version, as there may have been bug fixes or improvements related to font handling.

  5. Test with Different Files: Try converting other PPT files to see if the issue is consistent across different documents. This can help determine if the problem is specific to the file you are using.

Next Steps: If you continue to experience issues after trying these steps, please provide more details about the specific fonts used and any additional settings you might be applying during the conversion.

Let me know if this resolves your issue!

3

@dunghnguyen,
Thank you for reporting the issue. I have reproduced the problem where the text becomes larger when converting the PPT file to PPTX.

We have opened the following new ticket(s) in our internal issue tracking system and will deliver their fixes according to the terms mentioned in Free Support Policies.

Issue ID(s): SLIDESNET-45097

You can obtain Paid Support Services if you need support on a priority basis, along with the direct access to our Paid Support management team.

1 Like
4

The issues you found earlier (filed as SLIDESNET-45097) have been resolved in Aspose.Slides for .NET 25.10 (ZIP, MSI, NuGet, Cross-platform).
You can check all fixes on the Release Notes page.
You can also find the latest version of our library on the Product Download page.