Fuzzing but only at one direction

[broucaries]

Hi,

I have the following scanned text with a yellowish background that I want to remove.
http://nvlpubs.nist.gov/nistpubs/bullet ... 05_a2b.pdf

Under matlab I usually get the average of color here srgba(91%,80%,58%,1) set in hvs colorspace and remove all arround a fuzz 3D ellipsoid in HSV space.

Any idea to do better ?

Bastien

[snibgo]

I don't know what you are asking.

IM's "-fuzz" takes one parameter, which is the radius of a sphere in the 3D colour cube. (Or 4D, for CMYK). This is always a sphere, not ellipsoid. But you can get the same effect by first multiplying channels, or using "-level".

With a smarter script, you can find the mean colour of an area, and also the maximum and minimum, and calculate the fuzz that covers the entire range.

[fmw42]

try this on the first page. if you like it, then you can do all pages.

Code: Select all

convert -density 300 nbsbulletinv3n2p305_a2b.pdf[0] -colorspace gray -negate -lat 25x25+10% -negate result.pdf

[broucaries]

thanks it work better with +2%

[fmw42]

Adjust as desired, obviously.