Resizing of images results in terrible quality loss

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Rudolf Ladyzhenskii

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Jul 22, 2015, 5:00:15 AM7/22/15
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Hi all,

I tried to enable rewrite_images filter. This also turned on resize_images. Result is very ugly. I know, any image resize is a loss, but resizing to some small sizes (thumbnails) results in unbearable loss of quality.

So, question is -- is there an option to specify minimal image size to resize to?


Thanks,
Rudolf

Jan-Willem Maessen

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Jul 22, 2015, 1:00:01 PM7/22/15
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Hi Rudolf –

On Wed, Jul 22, 2015 at 5:00 AM, Rudolf Ladyzhenskii <ruma...@gmail.com> wrote:
Hi all,

I tried to enable rewrite_images filter. This also turned on resize_images. Result is very ugly. I know, any image resize is a loss, but resizing to some small sizes (thumbnails) results in unbearable loss of quality.

I'd be interested in seeing examples of images that do badly when they're resized like this, as it can help us to tune our resizing heuristics.  Our of curiosity, is the loss of quality evident at normal size, or when zooming (say on a mobile device)?  I ask because we have a filter to introduce responsive image tagging for downscaled images in the next release of mod_pagespeed.  If that's your use case today, you probably want to consider turning off image resizing.
 
So, question is -- is there an option to specify minimal image size to resize to?

There isn't.  We'd prefer to get image downscaling correct rather than turn it off.  Beyond turning off image resizing, you might also consider adjusting the ImageRecompressionQuality setting (or the JpegRecompressionQuality and the WebpRecompressionQuality).

-Jan 


 


Thanks,
Rudolf

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Jeff Kaufman

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Jul 22, 2015, 1:31:34 PM7/22/15
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Rudolf Ladyzhenskii

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Jul 22, 2015, 8:06:42 PM7/22/15
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Sorry, I did create two posts of same nature, but I was sure I deleted one of them.
Anyway, if this one can be deleted, it will be great.

Rudolf
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