From 91ea92686da2d0e6ee11e689c6d666e5fd70723b Mon Sep 17 00:00:00 2001
From: Troy Rollo <troy@enterprise.troy.rollo.name>
Date: Sun, 13 Mar 2011 10:07:33 +1100
Subject: [PATCH] hp3500.c: Remove interdependency between contrast and
 brightness

---
 ChangeLog        | 4 ++++
 backend/hp3500.c | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 7698c325a..2bb0e6f73 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2011-03-12 Troy Rollo <sane@troy.rollo.name>
+	* backend/hp3500.c: Remove interdependency between contrast and
+	  brightness.
+
 2011-03-12 Julien Blache <jb@jblache.org>
 	* doc/scanimage.man: batch-start defaults to 1 if not specified,
 	  not 0. Reported by Jakub Wilk <jwilk@debian.org>.
diff --git a/backend/hp3500.c b/backend/hp3500.c
index 08b599958..48a80352f 100644
--- a/backend/hp3500.c
+++ b/backend/hp3500.c
@@ -3349,7 +3349,7 @@ rts8801_scan (unsigned x,
 	    double contrast_adjust = (double) (contrast + 1) / 64;
 
 	    multnow = f * 64 * contrast_adjust;
-	    offnow = 4 * g - brightness - 64.0l * (1.0l - contrast_adjust);
+	    offnow = 4 * g + 128 - brightness;
 	  }
 	  if (multnow < 0)
 	    multnow = 0;