Landscape image to portrait with opencv

I have a method that does some processing on an IplImage and the method works as it should if the image is 640x480 pixels. But if it开发者_JAVA技巧 is 480x640 pixels, it does't not... because the image needs to be rotated to become 640x480 again, but then I need to rotate it back to 480x640 or translate ther coordinates taken from cvHaarDetectObjects to 480x640.

Can anybody tell me how can I do this?

thanks!!

Try transpose followed by flip. The flip is needed because transpose leaves an mirrored image when compared to the results of a rotation. If the algorithm can work with the mirrored image directly, I would recommend simply flipping the coordinate values of the detection result, rather than flipping the input image.

(Disclaimer: I haven't tried transpose or flip on multi-channel images)