very different results in Imagemagick 6.7.8-9 vs 7.0.8-53 and confused about fuzz option

[adrianTNT]

I have this image kindle.jpg, while trying to simplify the image for better OCR results, I noticed that it gives different results in version 6.7.8-9 2019-02-01 vs latest version 7.0.8-53

The same command I am trying on both results below is:

Code: Select all

convert ocr_test/kindle.jpg -fill white -colorspace gray -threshold 20% temp/test.jpg

Also with both versions I see no difference if I specify -fuzz 5% or -fuzz 90%
is this a bug ?

original:


converted with 6.7.8-9 2019-02-01


converted with 7.0.8-53

[snibgo]

V6.7.8 is very very old, and had some peculiarities.

"-fuzz" is a setting that affects the behaviour of some operations (eg "-opaque"), but you don't use any of those operations.