gtk image drawing

[Sylvia Lopez <sylvia lopez obs u-bordeaux1 fr>]

Hello,
first, sorry for my english.

my answer : i have to create an gtk+ interface who can display an image, 
zoom, get the x y and value of the pixel (on mouse over), and select a 
region (rectangle).
For the image i had used GtkImage but whe can't draw (?)
I had tryed to use GtkDrawingArea, I'm reading docs since days and days, 
I think there is something that I don't understand for instance (maybe 
it's so simple ? ;-) )
Can you tell me witch widget I have to use and how can I do that.

Thank you for your help
syl