// Method getImageString renders the imageObj into image data and returns
// it as a string.  Inspired by and used like the saveImage() method.  Python
// only at this time.  Questions and comments to Sean Gillies <sgillies@i3.com>
#ifdef SWIGPYTHON
    PyObject *getImageString(
        int imagetype,
        int transparent,
        int interlace,
        int quality)
    {
        unsigned char *imgbytes;
        int size;
        PyObject *imgstring;

        if (interlace) gdImageInterlace(self->bytes, 1);
        if (transparent) gdImageColorTransparent(self->bytes, 0);

        switch(imagetype) {
            case(MS_GIF):
                msSetError(MS_MISCERR, "GIF output is not available.", "saveImageString()");
                return(MS_FAILURE);
                break;
            case(MS_PNG):
#ifdef USE_GD_PNG
                imgbytes = gdImagePngPtr(self->bytes, &size);
#else
                msSetError(MS_MISCERR, "PNG output is not available.", "saveImageString()");
                return(MS_FAILURE);
#endif
                break;
            case(MS_JPEG):
#ifdef USE_GD_JPEG
                imgbytes = gdImageJpegPtr(self->bytes, &size, quality);
#else
                msSetError(MS_MISCERR, "JPEG output is not available.", "saveImageString()");
                return(MS_FAILURE);
#endif
                break;
            case(MS_WBMP):
#ifdef USE_GD_WBMP
                imgbytes = gdImageWBMPPtr(image->bytes, &size, 1);
#else
                msSetError(MS_MISCERR, "WBMP output is not available.", "saveImageString()");
                return(MS_FAILURE);
#endif
                break;
            default:
                msSetError(MS_MISCERR, "Unknown output image type.", "saveImageString()");
                return(MS_FAILURE);
        }

        // Create a Python string from the (char *) imgbytes.
        // The gdImage*Ptr functions return a size for just this purpose.
        imgstring = PyString_FromStringAndSize(imgbytes, size);

        // The gd docs recommend gdFree()
        gdFree(imgbytes);

        return imgstring;
    }
#endif