Progressive jpegs aka. interlace true or -interlace plane

[jimboolio]

Hello!

Is it possible to generate progressive jpgs with this library? I did not find any directions in docs or in other git issues here.

According to the libvips git issues, that library supports those with option interlace: true which I tried to set in image_options, but that did not work.

This is what I tried:

picture:
  source: assets/images/
  output: assets/images/
  image_options:
    jpg:
        interlace: true
    jpeg:
        interlace: true

The Jekyll conversion process shows me this: WARNING: The convert command is deprecated in IMv7, use "magick" which suggests me that the library is actually using imagemagic instead of the libvips. If the conversion is using imagemagic, I'd assume the option should be -interlace Plane instead, or something yaml formattable, I do not know what.

I tried this:

picture:
  source: assets/images/
  output: assets/images/
  image_options:
    jpg:
        interlace: Plane
    jpeg:
        interlace: Plane

My assumption of being able to use some custom options probably documented somehow in some upstream library would get me proper custom options and a collection of progressive jpg:s as a result, but I'm not sure about that. I tried to understand the code, it looks like the image_options would be a way to provide custom options to the underlying libvips or imagemagic libraries.

It is my first time trying Jekyll and I have not touched Ruby that many times before so my assumption of this kind of an custom option might be very wrong.

Regardless of what I have so far tried in those image_options I still get pictures, but according to some random website, the results are not progressive jpgs. But honestly I'd be surprised if it would have been this easy.

The reason I'm looking such option is that I'm expecting that my upcoming blog readers would often have very poor internet - because I often have in my area, so I expect that progressive jpg would bring quite some value to the reader experience.