Larry Lynn created PDFBOX-5852: ---------------------------------- Summary: Performance enhancements with type 4 shading Key: PDFBOX-5852 URL: https://issues.apache.org/jira/browse/PDFBOX-5852 Project: PDFBox Issue Type: Wish Components: Rendering Affects Versions: 2.0.28 Reporter: Larry Lynn
We've observed excessive CPU and memory consumption when converting a PDF to images when the PDF contains type 4 shading. This is especially noticeable when the conversion is done with a high DPI. Can this be improved? Conversation from the PDFBox users mailing list follows Initial email: {code:java} Hi CPU and memory usage when converting a PDF with type 4 shadingHello PDFBox users and maintainers, We have a PDF that causes performance problems when we use PDFBox to convert it to an image with renderImageWithDPI(). We're calling renderImageWithDPI() with 650 DPI. I realize this is a very high value - we're using it for high fidelity original images that will later be downsampled. On my work laptop which has fairly strong hardware, the conversion takes 25 minutes and consumes 20GB of memory. CPU and memory usage is reduced if we use a lower DPI. The PDF is 1 page long. It contains type 4 shading / Gouraud free form triangle meshes. We've been aware of some performance issues with type 4 shading for a little while now, but the PDFs that contained the type 4 shading belonged to our customers and we were not authorized to share them. We finally found a problem input document that is non-sensitive and that we are authorized to share. I've attached a copy of the problem PDF to this email. I searched the archives for the users and the developers mailing list and I didn't find anything specifically about this issue. I searched through the PDFBox jira tickets and I found a couple of tickets that looked similar: PDFBOX-2901 & PDFBOX-4491. PDFBOX-2901 seems to most closely describe what we're seeing, but that was closed in PDFBox 2.0.0, and our issue still reproduces with PDFBox 2.0.28. Should I refer this issue over to the developers mailing list or create a PDFBox Jira ticket for this? Thanks and Regards, Larry Lynn {code} Response: {code:java} Hi, Yes shading can be very slow, especially at high dpi. The attachment didn't get through, please upload to a sharehoster or create a ticket. If you need to register then add a meaningful text, e.g. the subject of this post so we know you're not a spammer. Also retry with 2.0.31 and 3.0.2 just to be sure. However I'm pessimistic that this can be fixed. Tilman {code} -- This message was sent by Atlassian Jira (v8.20.10#820010) --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@pdfbox.apache.org For additional commands, e-mail: dev-h...@pdfbox.apache.org