**  [image size].width = imageWidth * 2  **

[btn setImageEdgeInsets:UIEdgeInsetsMake((btnHeight-titleHeight-imageHeight)/2.0,
                                              (btnWidth-imageWidth)/2,
                                              titleHeight+(btnHeight-titleHeight-imageHeight)/2.0,
                                              (btnWidth-imageWidth)/2)];

[btn setTitleEdgeInsets:UIEdgeInsetsMake(btnHeight-titleHeight, 0, 0, 0)];

[btn setTitleEdgeInsets:UIEdgeInsetsMake(btnHeight-titleHeight, -imageWidth, 0, 0)];

[btn setTitleEdgeInsets:UIEdgeInsetsMake(btnHeight-titleHeight, -imageWidth*2, 0, 0)];