From f7bd53c0d3aefffba0a0a1622511dd7d260cfc8c Mon Sep 17 00:00:00 2001
From: Dane Springmeyer <dane@dbsgeo.com>
Date: Thu, 25 Oct 2012 13:30:14 -0700
Subject: [PATCH] make a note about what Z_DEFAULT_COMPRESSION means to zlib

---
 src/image_util.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/image_util.cpp b/src/image_util.cpp
index 741e07eda..1dc163bf8 100644
--- a/src/image_util.cpp
+++ b/src/image_util.cpp
@@ -270,7 +270,7 @@ void save_to_stream(T const& image,
         if (t == "png" || boost::algorithm::starts_with(t, "png"))
         {
             int colors  = 256;
-            int compression = Z_DEFAULT_COMPRESSION;
+            int compression = Z_DEFAULT_COMPRESSION; // usually mapped to z=6 in zlib
             int strategy = Z_DEFAULT_STRATEGY;
             int trans_mode = -1;
             double gamma = -1;