a,b,c,d,e,f,g,h are the coefficients of the perspective transform. look at http://alumni.media.mit.edu/~cwren/interpolator/ for a brief introduction (look for the fraction formula x= (ax+by+c)/(gx=hy+1)
On Sun, May 16, 2010 at 9:51 AM, PyProg PyProg <pypro...@gmail.com> wrote: > 2010/5/3 Fredrik Lundh <fred...@pythonware.com>: > >> I've added the documentation from the original patch to this page: >> >> http://effbot.org/tag/pil.Image.Image.transform >> >> The next text is attached below. >> >> </F> >> >> im.transform(size, PERSPECTIVE, data) >> >> im.transform(size, PERSPECTIVE, data, filter) >> >> Applies a perspective transform to the image, and places the result >> in a new image with the given size. >> >> Data is a 8-tuple (a, b, c, d, e, f, g, h) which contains the >> coefficients for a perspective transform. For each pixel (x, y) >> in the output image, the new value is taken from a position >> (a x + b y + c)/(g x + h y + 1), (d x + e y + f)/(g x + h y + 1) >> in the input image, rounded to nearest pixel. >> >> This function can be used to change the 2D perspective of the >> original image. > > Hello > > The problem is that I do not understand what that means: "which > Contains the coefficients for a perspective transform ... "... and in > particular what exactly match a, b, c, d, e, f, g and h. > > If you are patient (excuse me), can you explain with precision (and a > didactic, for someone who has trouble like me) what these data (and > possibly with an example of processing with good values for a, b, c, > d, e, f , g and h). > > Thank you in advance. > > a+ > > -- > http://ekd.tuxfamily.org > http://ekdm.wordpress.com > http://lprod.org/wiki/doku.php/video:encodage:avchd_converter > _______________________________________________ > Image-SIG maillist - image-...@python.org > http://mail.python.org/mailman/listinfo/image-sig > _______________________________________________ Image-SIG maillist - Image-SIG@python.org http://mail.python.org/mailman/listinfo/image-sig
