Image gradient?

On this page its said that the gradient points in the direction of most
increase in intensity:

http://en.wikipedia.org/wiki/Image_gradient

but why are all the arrows pointing toward the black area? Is white not
defined as having the highest intensity?


.

Relevant Pages

  • Re: Which software could do that?
    ... Apply a filter to the image, with _an intensity that is proportional to the gradient in the shape_. ... I dont know if imagemagick is ok ...
    (sci.image.processing)
  • Re: gradient of a plot
    ... polang being on the x-axis while intensity on the yaxis ... I want to find the gradient of a plot which is a plot of polang,intensity, but i get the following error, ...
    (comp.soft-sys.matlab)
  • Re: Image gradient?
    ... but why are all the arrows pointing toward the black area? ... defined as having the highest intensity? ... Not sure what you mean by downhill direction. ...
    (sci.image.processing)