I have noticed that I am not allowed to update a file after I've opened it with Fl_PNG_Image.

I use:

Fl_Image* image;

:

:

Fl_Image* raw_image = new Fl_PNG_Image(filename);

// calculate new image size after scaling to fit

image = raw_image->copy(new_w, new_h);

delete raw_image;

I have only a feeing this is happening. I just want to rule out that Fl_Image (or its heirs) is locking the file. Depending on the file extension, I use Fl_PNG_Image or JPG or BMF

Thanks Phil.