Overwrite ImageMagick params

[philipgiuliani]

Its possible to overwrite ImageMagick params that are set in generate_simple_captcha_image like the -pointsize or -gravity?
https://github.com/pludoni/simple-captcha/blob/master/lib/simple_captcha/image.rb#L67

I tried the following

sc.add_image_style('custom', [
      "-background '#FFFFFF'",
      "-fill '#6abc89'",
      "-pointsize 30"])

would be cool if the image style gets merged after the default settings, so that it could be overwritten.