<story><title>Magic PNG Thumbnails</title><url>http://thume.ca/projects/2012/11/14/magic-png-files/</url></story><parent_chain><item><author>pygy_</author><text>Could someone explain why this image is flickering on my MacBook Air screen?&lt;p&gt;&lt;a href=&quot;http:&amp;#x2F;&amp;#x2F;thume.ca&amp;#x2F;assets&amp;#x2F;postassets&amp;#x2F;doubleVision&amp;#x2F;out.png&quot; rel=&quot;nofollow&quot;&gt;http:&amp;#x2F;&amp;#x2F;thume.ca&amp;#x2F;assets&amp;#x2F;postassets&amp;#x2F;doubleVision&amp;#x2F;out.png&lt;/a&gt;&lt;p&gt;Especially &amp;quot;ze first&amp;quot; image as seen in FF and Chrome.&lt;p&gt;I suppose it is related to how monitors use temporal dithering to fake 24 bit colors when they really have 18 bits per pixel, but why is it more apparent on this kind of picture?&lt;p&gt;Is it a perceptual issue or a technical one?&lt;p&gt;It is also apparent when using Windows XP under virtualization. Some windows have checkerboard patterns that flicker.</text></item></parent_chain><comment><author>sp332</author><text>Here&amp;#x27;s a page with a test and a potential explanation &lt;a href=&quot;http:&amp;#x2F;&amp;#x2F;www.lagom.nl&amp;#x2F;lcd-test&amp;#x2F;inversion.php&quot; rel=&quot;nofollow&quot;&gt;http:&amp;#x2F;&amp;#x2F;www.lagom.nl&amp;#x2F;lcd-test&amp;#x2F;inversion.php&lt;/a&gt;</text></comment>
<story><title>Magic PNG Thumbnails</title><url>http://thume.ca/projects/2012/11/14/magic-png-files/</url></story><parent_chain><item><author>pygy_</author><text>Could someone explain why this image is flickering on my MacBook Air screen?&lt;p&gt;&lt;a href=&quot;http:&amp;#x2F;&amp;#x2F;thume.ca&amp;#x2F;assets&amp;#x2F;postassets&amp;#x2F;doubleVision&amp;#x2F;out.png&quot; rel=&quot;nofollow&quot;&gt;http:&amp;#x2F;&amp;#x2F;thume.ca&amp;#x2F;assets&amp;#x2F;postassets&amp;#x2F;doubleVision&amp;#x2F;out.png&lt;/a&gt;&lt;p&gt;Especially &amp;quot;ze first&amp;quot; image as seen in FF and Chrome.&lt;p&gt;I suppose it is related to how monitors use temporal dithering to fake 24 bit colors when they really have 18 bits per pixel, but why is it more apparent on this kind of picture?&lt;p&gt;Is it a perceptual issue or a technical one?&lt;p&gt;It is also apparent when using Windows XP under virtualization. Some windows have checkerboard patterns that flicker.</text></item></parent_chain><comment><author>Kronopath</author><text>I expect this is due to a Moiré pattern between your monitor&amp;#x27;s pixel grid and the &amp;quot;dots&amp;quot; in the image.</text></comment>