Map depth image in Unorm16 for full range

The mapping from Unorm16 encoded depth images did map half of the range
to the max color value, hence causing that the same gray tones were used
twice, for values < 0.5 (0x8000 before unorm), or >= 0.5.
Fixing the normalization to linearly map the whole range.

framework/util/image_writer.cpp

@@ -273,8 +273,8 @@ static const uint8_t* ConvertIntoTemporaryBuffer(uint32_t    width,
                 for (uint32_t x = 0; x < width; ++x)
                 {
                     const uint32_t normalized_depth = bytes_u32[x] & 0x00FFFFFF;
-                    const float    float_depth      = static_cast<float>(normalized_depth) / 8388607.0f;
-                    const uint8_t  depth            = static_cast<uint8_t>(float_depth * 255.0f);
+                    const float    float_depth = static_cast<float>(normalized_depth) / static_cast<float>(0xffffff);
+                    const uint8_t  depth       = static_cast<uint8_t>(float_depth * 255.0f);
 
                     *(temp_buffer++) = depth;
                     *(temp_buffer++) = depth;
@@ -301,7 +301,7 @@ static const uint8_t* ConvertIntoTemporaryBuffer(uint32_t    width,
                 for (uint32_t x = 0; x < width; ++x)
                 {
                     const uint16_t normalized_depth = bytes_u16[x];
-                    const float    float_depth      = static_cast<float>(normalized_depth) / 32767.0f;
+                    const float    float_depth      = static_cast<float>(normalized_depth) / static_cast<float>(0xffff);
                     const uint8_t  depth            = static_cast<uint8_t>(float_depth * 255.0f);
 
                     *(temp_buffer++) = depth;