sample-factor

[cujsmith]

a) Is there function in Magick++ to apply desired chroma subsampling factor (like the command line "-sampling-factor")?
b) Further, I understand that by default, when writing jpeg images, 4:2:0 subsampling will be applied by default up to quality factor 90; above 90, no subsampling will occur by default. Assuming a) above can be achieved, is there a way to force 4:2:0 subsampling on images written with quality factor greater than 90?
Thanks!

[snibgo]

(a) At a guess, Magick::Options::samplingFactor() looks likely.

I don't know about your other questions.

[cujsmith]

Thanks again snibgo, I got it working with defineValue.