

I've added the documentation from the original patch to this page:
http://effbot.org/tag/pil.Image.Image.transformThe 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 8tuple (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.
On Wed, Apr 28, 2010 at 11:59 PM, PyProg PyProg < [hidden email]> wrote:
_______________________________________________
ImageSIG maillist  [hidden email]
http://mail.python.org/mailman/listinfo/imagesig


2010/5/3 Fredrik Lundh < [hidden email]>:
> 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 8tuple (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.orghttp://ekdm.wordpress.comhttp://lprod.org/wiki/doku.php/video:encodage:avchd_converter_______________________________________________
ImageSIG maillist  [hidden email]
http://mail.python.org/mailman/listinfo/imagesig


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 < [hidden email]> wrote:
> 2010/5/3 Fredrik Lundh < [hidden email]>:
>
>> 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 8tuple (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> _______________________________________________
> ImageSIG maillist  [hidden email]
> http://mail.python.org/mailman/listinfo/imagesig>
_______________________________________________
ImageSIG maillist  [hidden email]
http://mail.python.org/mailman/listinfo/imagesig

