Emmeran Seehuber created PDFBOX-4184: ----------------------------------------
Summary: [PATCH]: Support simple lossless compression of 16 bit RGB images Key: PDFBOX-4184 URL: https://issues.apache.org/jira/browse/PDFBOX-4184 Project: PDFBox Issue Type: Improvement Components: Writing Affects Versions: 2.0.9 Reporter: Emmeran Seehuber Attachments: pdfbox_support_16bit_image_write.patch The attached patch add support to write 16 bit per component images correctly. I've integrated a test for this here: [https://github.com/rototor/pdfbox-graphics2d/commit/8bf089cb74945bd4f0f15054754f51dd5b361fe9] It only supports 16-Bit TYPE_CUSTOM with DataType == USHORT images - but this is what you usually get when you read a 16 bit PNG file. This would also fix [https://github.com/danfickle/openhtmltopdf/issues/173]. The patch is against 2.0.9, but should apply to 3.0.0 too. There is still some room for improvements when writing lossless images, as the images are currently not efficiently encoded. I.e. you could use PNG encodings to get a better compression. (By adding a COSName.DECODE_PARMS with a COSName.PREDICTOR == 15 and encoding the images as PNG). But this is something for a later patch. It would also need another API, as there is a tradeoff speed vs compression ratio. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@pdfbox.apache.org For additional commands, e-mail: dev-h...@pdfbox.apache.org