Another round, using one of Rob's test images.
The directly scaled images look sharper.
I've now realized that our image scaler uses the -sharpen option in most
cases (as long as the thumbnail is 0.85 times the size of the original or
smaller, if I'm reading the code correctly). This time I applied -sharpen
0x0.8 to the right buckets in the chain (in this case every bucket except
4096) for a fairer comparison.
And this time instead of a side by side, there are two pages, so that you
can see the difference better by switching between tabs:
https://dl.dropboxusercontent.com/u/109867/imagickchaining/2/a.html
https://dl.dropboxusercontent.com/u/109867/imagickchaining/2/b.html
On Thu, May 1, 2014 at 7:47 PM, Erwin Dokter <erwin(a)darcoury.nl> wrote:
> On 01-05-2014 16:57, Gilles Dubuc wrote:
>
>> And here's a side-by-side comparison of these images generated with
>> chaining and images that come from our regular image scalers:
>>
https://dl.dropboxusercontent.com/u/109867/imagickchaining/index.html Try
>> to guess which is which before inspecting the page for the answer :)
>
> Not much difference, but it's there. Progressive scaling loses edge detail
> during each stage. The directly scaled images look sharper.
> Regards,
> --
> Erwin Dokter
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