From d73e63a7263c04e1c66b17c4276ed2dfb7e906cb Mon Sep 17 00:00:00 2001
From: Pascal Massimino <pascal.massimino@gmail.com>
Date: Tue, 22 May 2012 02:28:19 -0700
Subject: [PATCH] add DequantizeLevels() placeholder

will be called by alpha post-processing, although doing nothing for now.
Gradient smoothing would be nice-to-have here. Patch welcome!

Change-Id: I534cde866bdc75da22d0f0a6d1373c90e21366f3
---
 src/utils/quant_levels.c | 11 ++++++++++-
 src/utils/quant_levels.h |  5 +++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/utils/quant_levels.c b/src/utils/quant_levels.c
index 9bf1f870..8623d97d 100644
--- a/src/utils/quant_levels.c
+++ b/src/utils/quant_levels.c
@@ -142,13 +142,22 @@ int QuantizeLevels(uint8_t* data, int width, int height,
   }
 
   // Compute final mean squared error if needed.
-  if (mse) {
+  if (mse != NULL) {
     *mse = (float)sqrt(err);
   }
 
   return 1;
 }
 
+int DequantizeLevels(uint8_t* data, int width, int height) {
+  if (data == NULL || width <= 0 || height <= 0) return 0;
+  // TODO(skal): implement gradient smoothing.
+  (void)data;
+  (void)width;
+  (void)height;
+  return 1;
+}
+
 #if defined(__cplusplus) || defined(c_plusplus)
 }    // extern "C"
 #endif
diff --git a/src/utils/quant_levels.h b/src/utils/quant_levels.h
index 2523d16e..b3e804b5 100644
--- a/src/utils/quant_levels.h
+++ b/src/utils/quant_levels.h
@@ -27,6 +27,11 @@ extern "C" {
 int QuantizeLevels(uint8_t* data, int width, int height, int num_levels,
                    float* mse);
 
+// Apply post-processing to input 'data' of size 'width'x'height' assuming
+// source what quantized to a reduced number of levels.
+// Returns false in case of error (data is NULL, invalid parameters, ...).
+int DequantizeLevels(uint8_t* data, int width, int height);
+
 #if defined(__cplusplus) || defined(c_plusplus)
 }    // extern "C"
 #endif