Magick++ and Rotating

[magick]

When you rotate the image other than 90 degrees you are introducing transparency which caused the image to saved slightly differently. You may want to force a compliant BMP image by saving with a bmp3 prefix. For example, use the filename `bmp3:image.bmp'. The prefix forces the BMP image to be a type that your BitBlt() method may be more ameniable to.