Changeset 2014Tweet

Timestamp:

Nov 17, 2007, 4:02:59 PM (13 years ago)

Author:

Sam Hocevar

Message:

• Put a few keywords in bold.

File:

• www/study/part2.html (modified) (5 diffs)

www/study/part2.html

@@ -113 +113 @@
 
 <p> Different matrices can give very different results. This is a 4×4
-Bayer ordered dithering matrix: </p>
+<b>Bayer ordered dither matrix</b>: </p>
 
 <p style="text-align: center;">
@@ -135 +135 @@
 </p>
 
-<p> This 4×4 cluster dot matrix creates dot patterns: </p>
+<p> This 4×4 <b>cluster dot matrix</b> creates dot patterns: </p>
 
 <p style="text-align: center;">
@@ -190 +190 @@
 </p>
 
-<p> This is random dithering with threshold values chosen with a gaussian
-distribution (mean 0.5, standard deviation 0.15): </p>
+<p> This is random dithering with threshold values chosen with a <b>gaussian
+distribution</b> (mean 0.5, standard deviation 0.15): </p>
 
 <p style="text-align: center;">
@@ -202 +202 @@
 <p> Random dithering can help reduce the major problem caused by halftoning,
 which is the apparition of pattern artifacts. The method is as simple as
-slightly perturbating matrix coefficients (or pixel values) during the
-halftoning step. The difficult part is the proper pertubation choice. </p>
+<b>slightly perturbating dither matrix coefficients</b> (or pixel values)
+during the halftoning step. The difficult part is picking up an adequate
+perturbation function: too much perturbation and the result is unrecognisable,
+too little and the artifacts stay. </p>
 
 <p> For instance, this is the result of 8×8 Bayer dithering perturbated by a
@@ -216 +218 @@
 
 <p> Another way to use random number generators to avoid pattern artifacts
-is random dither matrix selection. The image space is no longer tiled with
-the same matrix over and over again, but with a random selection from a list
-of similar dither matrices. </p>
+is <b>random dither matrix selection</b>. The image space is no longer tiled
+with the same matrix over and over again, but with a random selection from a
+list of similar dither matrices. </p>
 
 <p> This example shows random matrix selection from a list of six 3×3 dither