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@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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