Start from ImageMagick 6.8, it will auto convert a black and white image(RGB) to be grayscale, which will make the altered image to be lighter than the original one. In ImageMagick 6.9, we can turn this feature off by using the command "-set colorspace:auto-grayscale=false". However, this option is not available in Wand latest version, is it a way I can turn off this feature by using Wand?
In addition, the command "-type truecolor" can also prevent Imagemagick convert the image to be grayscale. I try to set the image type to be "truecolor" by using "img.type = 'truecolor'" but the image is still converted to be grayscale, which is different behavior than the ImageMagick. Just want to know that is there something I did wrong or is there a way I can use to prevent black and white image to be converted into grayscale by using Wand?
In case anyone has the same issue.
You can use turn off auto-grayscale in wand.
with Image(filename='input.jpg') as img: img.metadata['colorspace:auto-grayscale'] = 'false'