Reading JPEG2000 images takes too long

[Charltsing]

Magick.NET version

13.10.0

Environment (Operating system, version and so on)

Windows10, net framework 4.7.2

Description

I tried to read a Jpeg2000 image with a width of 6622 and a height of 4689, which took 6 seconds. Is this normal time?
How to optimize the time spent reading JPEG2000

JPXDecode.zip

settings.SetDefines(new Jp2ReadDefines
{
QualityLayers = 100,
});

[dlemstra]

This is slow because of two reasons. I takes quite some time to decode the jp2 image and then also some time to copy this decoded data to our image data. And because of how this information is stored it makes it more difficult/expensive to copy the pixel data.

The copy action could be improved so I just pushed a patch to make the part that copies the pixels twice as fast. The other part is out of our control. This change will not become available in the next release because I was already preparing this and don't want to include this change at the last minute. So it might take a while before you will get this performance improvement.