Latest release (October 2025)

GroupDocs.Watermark 25.10 introduces important updates, performance improvements, and issue resolutions for a more stable and efficient workflow.

Full list of changes in this release

Major Features

Performance optimization for previewing large Word documents

🌐 The issue affected very large Word documents, where each page was rendered into an image sequentially, resulting in slow performance. The total processing time scaled linearly — the more pages, the longer it took. In the new release, the rendering process has been optimized, allowing all pages to be generated in roughly the same time it previously took to render a single page.

using (Watermarker watermarker = new Watermarker("sample.docx"))
{
    CreatePageStream createPageStreamDelegate = delegate(int number)
    {
        string previewImageFileName = Path.Combine(outputDirectory, string.Format("page{0}.png", number));
        return File.OpenWrite(previewImageFileName);
    };

    ReleasePageStream releasePageStreamDelegate = delegate(int number, Stream stream)
    {
        stream.Close();
    };

    PreviewOptions previewOptions = new PreviewOptions(createPageStreamDelegate, releasePageStreamDelegate)
    {
        PreviewFormat = PreviewOptions.PreviewFormats.PNG,
        PageNumbers = new []{1, 2, 3}
    };
    
    watermarker.GeneratePreview(previewOptions);
}

High Memory Usage and Long Processing Time with Large TIFF Files

🌐 We’ve optimized the watermarking process for large TIFF files, delivering much faster performance on Windows and up to 20% higher efficiency on Linux.