Reply to thread

Message

<blockquote data-quote="Scythe42" data-source="post: 878879" data-attributes="member: 95833">In fact what feels natural to you is illogical...&nbsp;Looks like you are misunderstanding &quot;blocky&quot; with aliasing. Resizing never makes the picture more blocky...&nbsp;Scaling introduces three types of artficats:<ul>
<li data-xf-list-type="ul">blurriness</li>
<li data-xf-list-type="ul">aliasing</li>
<li data-xf-list-type="ul">ringing</li>
</ul>And these are the ones you want to limit.&nbsp;With blurring before resizing you reduce the original artifacts in the SD source and also limit the aliasing the resizing operation introduces. And to reduce the blurriness a resizing operation introduces (resizing itself is a kind of noise reducer) you want to sharpen the result a bit. This approach also reduces the ringing.&nbsp;Sharpening (in itself a noise introducer) should also be performed on 1080p scene rips as well to reduce the compression artifacts, but only a tiny amount. For original blurays there isn't much you can do, so leave them untouched. For xvid, don't blur but deblock (very agressive blurring...) to make them at least a bit watchable.&nbsp;Blurring after resizing just makes the picture even more blurry and does nothing to the picture quality. In fact you even lose more details and put way more stress on your GPU/CPU for a worse result. The same detail loss happens if you blur the original image too much.&nbsp;Try it for yourself in Photoshop for example or read any book ever published on digital image post-processing...&nbsp;PS: Usually for SD sources scaled up to 1080p it would be better to scale the picture up to 2x1080, do the sharpening and then scale it down to 1x1080p. This will be even nicer for SD sources.</blockquote>

[QUOTE="Scythe42, post: 878879, member: 95833"] In fact what feels natural to you is illogical... Looks like you are misunderstanding "blocky" with aliasing. Resizing never makes the picture more blocky... Scaling introduces three types of artficats: [LIST] [*]blurriness [*]aliasing [*]ringing [/LIST] And these are the ones you want to limit. With blurring before resizing you reduce the original artifacts in the SD source and also limit the aliasing the resizing operation introduces. And to reduce the blurriness a resizing operation introduces (resizing itself is a kind of noise reducer) you want to sharpen the result a bit. This approach also reduces the ringing. Sharpening (in itself a noise introducer) should also be performed on 1080p scene rips as well to reduce the compression artifacts, but only a tiny amount. For original blurays there isn't much you can do, so leave them untouched. For xvid, don't blur but deblock (very agressive blurring...) to make them at least a bit watchable. Blurring after resizing just makes the picture even more blurry and does nothing to the picture quality. In fact you even lose more details and put way more stress on your GPU/CPU for a worse result. The same detail loss happens if you blur the original image too much. Try it for yourself in Photoshop for example or read any book ever published on digital image post-processing... PS: Usually for SD sources scaled up to 1080p it would be better to scale the picture up to 2x1080, do the sharpening and then scale it down to 1x1080p. This will be even nicer for SD sources. [/QUOTE]

Verification