Changeset 1980Tweet

Timestamp:

Nov 16, 2007, 4:11:15 PM (13 years ago)

Author:

Sam Hocevar

Message:

• Added a 4-colour example to the grayscale dithering part.

Location:

www/study

Files:

• grad4-2-3.png (added)
• out4-2-3.png (added)
• part4.html (modified) (1 diff)
• study.py (modified) (2 diffs)

www/study/part4.html

@@ -154 +154 @@
 come up with. </p>
 
+<p> Finally, this is gamma-corrected 4-colour dithering: </p>
+
+<p style="text-align: center;">
+  <img src="out4-2-3.png" width="256" height="256"
+       class="inline" alt="Floyd-Steinberg, 4 colours, gamma-corrected" />
+  <img src="grad4-2-3.png" width="32" height="256"
+       class="inline" alt="Floyd-Steinberg, 4 colours, gamma-corrected gradient" />
+</p>
+
 <div style="float: left;">
    <a href="part3.html">Error diffusion &lt;&lt;&lt;</a>

www/study/study.py

@@ -442 +442 @@
 # Output 4.2.1: gamma-corrected 2-colour Floyd-Steinberg
 # Output 4.2.2: gamma-corrected 3-colour Floyd-Steinberg
+# Output 4.2.3: gamma-corrected 4-colour Floyd-Steinberg
 def test42x(src, mat, threshold):
     (w, h) = src.size()
@@ -495 +496 @@
 test42x(lenna256bw, ERROR_FSTEIN, threshold_3).writePng("out4-2-2.png")
 test42x(gradient256bw, ERROR_FSTEIN, threshold_3).writePng("grad4-2-2.png")
+test42x(lenna256bw, ERROR_FSTEIN, threshold_4).writePng("out4-2-3.png")
+test42x(gradient256bw, ERROR_FSTEIN, threshold_4).writePng("grad4-2-3.png")
 
 # Pattern 5.0.1: 8-colour palette