Question

I am making a small photo editing application using wxPython ogl.ShapeCanvas. I can load images on the canvas. I just want to know how will I adjust the brightness/contrast of an image inside the canvas (using a slider).

Thanks

Answer 1

Hope it’s not to late to be of any help, but…I had to do something similar with OGL recently when I wanted to adjust the transparency on the fly. What I ended up doing was creating a class that made the adjustments and returned a wx.Bitmap, then I had a ShapeCanvas subclass use the adjusted picture, e.g.

class PicAdjuster(cls):    
    def adjust_pic(self, image_filename, factor_red = 1., factor_green = 1., factor_blue = 1., factor_alpha = 1.):
        original_img = wx.Image(image_filename)
        adjusted_img = original_img.AdjustChannels(factor_red, factor_green, factor_blue, factor_alpha)
        return wx.BitmapFromImage(adjusted_img)

then for the ShapeCanvas:

class PicDisplay(ogl.ShapeCanvas):
    def add_picture(self, image_filename):
        new_img = ogl.BitmapShape()
        add_alpha = PicAdjuster()
        new_img.SetBitmap(add_alpha.adjust_pic(factor_alpha = 0.5))
        self.diagram.AddShape(new_img)

Anyway, you might be able to do something similar to make your adjustments; just use your picture adjuster and call the ogl.BitmapShape’s SetBitmap() method as required.