Re: Relative positioning

[Urs H. <ur...@an...>]

Christian Walther wrote:
> Urs Holzer wrote:
>> Do you think the following has a chance to work?
>> I render my patches with Povray using the partial rendering options
>> StartColumn, StartRow, EndColumn, EndRow by giving relative
>> coordinates (i.e. numbers between 0 and 1). Then I crop the images
>> with ImageMagick, again giving relative coordinates. At the end, I
>> place the patch in Pipmak using relative coordinates.
>> I fear that this is doomed to result in ugly artifacts.
> 
> That should work, provided that you deal with the following: I assume
> that both POV-Ray and ImageMagick round your relative numbers to whole
> pixels. Pipmak doesn't do that. So you need to make sure that the
> boundaries you give in relative coordinates already lie on pixel
> edges.

Ok, I give it up. It seems, that ImageMagick does treat offsets always
as pixels, only the _size_ of the region to be cropped out can be given
as percentage. I could use ImageMagick's -trim, which cuts off
uniformly coloured areas from all borders, but I don't know whether it
would always do the right thing. I don't even dare to think about how
to solve the problem you mentioned.