Please disable default image sharpening in the VIPS backend

[pyridine]

Hi, this is related to carrierwaveuploader/carrierwave#2481 and #67
Default image sharpening was disabled a while back in the ImageMagick backend, but not in the VIPS backend. I think it should be disabled by default in both. The default sharpening behavior is not expected and can degrade/change the image quality.

Here are the results of resizing an image in VIPS vs ImageMagick:

Base image

Converted with ImageMagick backend

Converted with VIPS backend

As with the original issue, the ImageMagick-processed image has not changed (much?), while VIPS-processed image appears lower quality, or at least different, which is not expected.

I used this code:

processed = ImageProcessing::Vips # or MiniMagick
  .source(base_image)
  .resize_to_fit(1280,720) # the image is already this size, so this shouldn't change anything
  .convert("png")
  .call

[midnight-wonderer]

Your eyes are really good; I couldn't tell the difference.
For those who are like me, here is where to look:

Created with: _ttps:https://www.diffchecker.com/image-compare/

P.S. I could see it in the original post once pointed out.

[janko]

I plan to disable automatic sharpening in libvips for the upcoming major release. I agree it's unexpected, and it would be consistent with disabling it for the MiniMagick backend. I will still keep a default sharpen mask that can be turned on.

[formigarafa]

I'm impressed with what you guys can see. Thank you for that, but I didn't. ❤️