From 57ad405b8da9397320bfcb9d76a63e44266afa49 Mon Sep 17 00:00:00 2001
From: James R. Barlow <james@purplerock.ca>
Date: Mon, 15 Sep 2025 13:25:33 -0700
Subject: [PATCH] Avoid unnecessary re-compression in QPDFJob::doCheck

---
 libqpdf/QPDFJob.cc | 5 +++++
 1 file changed, 5 insertions(+), 0 deletions(-)

diff --git a/libqpdf/QPDFJob.cc b/libqpdf/QPDFJob.cc
index 560bead..81bded8 100644
--- a/libqpdf/QPDFJob.cc
+++ b/libqpdf/QPDFJob.cc
@@ -793,6 +793,11 @@ QPDFJob::doCheck(QPDF& pdf)
         Pl_Discard discard;
         w.setOutputPipeline(&discard);
         w.setDecodeLevel(qpdf_dl_all);
+        // Disable compression of streams, since we only need to confirm we can decode them. This
+        // avoids JPEG DCT -> Flate recompression of all images.
+        w.setCompressStreams(false);
+        // Also disable recompression of Flate streams since are only checking.
+        w.setRecompressFlate(false);
         w.write();
 
         // Parse all content streams
--
libgit2 0.21.4