Picture manipulation with Lazarus, like distortion correction
lazarus / 39-Graphics

----------------------------------------------------------------------
stephanweber · 2024-01-15 13:40

Hi,

I want to read-in a jpg photo and manipulate it. E.g. A) I want that
the straight lines of a house become perpendicular to each other, or
B) I want to compensate the distortion of a lense (e.g. wide-angle
lense often bend straight lines a bit).
For A) I would apply a linear distortion, like expanding the upper
rows more than the lower ones, and for B) I may need to expand the
outer columns a bit. 
To support the operation, I would like to see the original photo in a
picture box, and the manipulated one in a 2nd box. If the user
parameters to be entered are fine (like the amount of correction), I
would export the result to a new jpg.
How can I access and manipulate the pixels?

Bye Stephan

----------------------------------------------------------------------
wp · 2024-01-15 15:23

Take a look at BGRABitmap, unit bgrafilters. Not exactly what you
want, but you may get an idea how to implement it.