It looks like the inside / outside logic behind the MagickImage.Clip method has been flipped. We clip images and create transparent backgrounds using this code:
img.Alpha(AlphaOption.Transparent);
img.Clip(name, true);
img.Alpha(AlphaOption.Opaque);
Previously with v 6.8.9.501, the clipping was:
https://www.dropbox.com/s/kq5zsour2mzbgjq/894150_old_false.png?dl=0
https://www.dropbox.com/s/crdgcuey1nnbia1/894150_old_true.png?dl=0
Original:
https://www.dropbox.com/s/kes3hs6z58ntr87/894150.jpg?dl=0
Clipped with flag = true
https://www.dropbox.com/s/avdlm2qo5su9lrk/bad.png?dl=0
Clipped with flag = false
https://www.dropbox.com/s/5rqyos9xtim3gbj/good.png?dl=0
Comments: I can confirm and reproduce your issue. I am not sure yet if this change is by accident or something that we could finally fix in ImageMagick 7. I will have get back to you on this.
img.Alpha(AlphaOption.Transparent);
img.Clip(name, true);
img.Alpha(AlphaOption.Opaque);
Previously with v 6.8.9.501, the clipping was:
https://www.dropbox.com/s/kq5zsour2mzbgjq/894150_old_false.png?dl=0
https://www.dropbox.com/s/crdgcuey1nnbia1/894150_old_true.png?dl=0
Original:
https://www.dropbox.com/s/kes3hs6z58ntr87/894150.jpg?dl=0
Clipped with flag = true
https://www.dropbox.com/s/avdlm2qo5su9lrk/bad.png?dl=0
Clipped with flag = false
https://www.dropbox.com/s/5rqyos9xtim3gbj/good.png?dl=0
Comments: I can confirm and reproduce your issue. I am not sure yet if this change is by accident or something that we could finally fix in ImageMagick 7. I will have get back to you on this.