Issue with Fonts Rendering Artifacts in PDF Conversion (PowerPoint to PDF) in Java

Hello,

I am using GroupDocs conversion java lib to convert PowerPoint files (.pptx) to PDF, but I am encountering an issue where some characters appear with artifacts after the conversion. The text becomes distorted, making it difficult to read.

I am using groupdocs-conversion version 24.12.1 in my Java21 application that is running on Ubuntu 24.04.1 LTS
I installed ttf-mscorefonts on the my ubuntu and I joined the output of fc-list
I am also joining the file I want to convert and the output I have.
The issue is only present in some PowerPoint files, not all of them.
Here is a snippet of the code I am using

        Path inputFilePath = Path.of("src/test/resources/input-sip").resolve("pptx_binaire.pptx");
        Path outputFile = Path.of("src/test/resources/sip").resolve("conversion_result.pdf");
        initializeLicense();
        ConverterSettings converterSettings = new ConverterSettings();
        converterSettings.setFontDirectories(List.of("/usr/share/fonts"));
        PdfConvertOptions pdfOptions = new PdfConvertOptions();
        pdfOptions.getPdfOptions().setPdfFormat(PdfFormats.Default);
        try (InputStream is = new FileInputStream(inputFilePath.toFile()); Converter converter = new Converter(() -> is
                , () -> converterSettings
        )) {
            converter.convert(outputFile.toString(), pdfOptions);
        }

Could you provide guidance on how to resolve this issue? Are there any specific font configurations or dependencies required for Linux environments?
input_pptx_binaire.zip (3,7 Mo)

conversion_result.zip (2,0 Mo)

fc-list-output.zip (10,2 Ko)

Thank you for your help.
input_pptx_binaire.zip (3.72 MB)
conversion_result.zip (2.05 MB)
fc-list-output.zip (10.2 KB)

Hello @frossard ,

Thank you for your inquiry and for sharing detailed information. We will do our best to investigate this issue promptly and provide you with updates. However, before proceeding, have you tested this conversion using the latest GroupDocs.Conversion fot Java 25.2.2 version?

@frossard
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): CONVERSIONJAVA-2802

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.