If i draw an image with the image mode VG_DRAW_IMAGE_MULTIPLY the 
alpha value behaves strange.
If alpha value is 1.0f the image is invisible.
If i set the alpha value to e.g. 0.9999f then it is drawn correctly and can be color transformed with VG_COLOR_TRANSFORM.

E.g. the following code:

        VGPaint colorPaint = vgCreatePaint();
        vgSeti(VG_IMAGE_MODE, VG_DRAW_IMAGE_MULTIPLY);
        VGfloat color[4] = {1.0f, 1.0f ,1.0f, 0.9999f};
        vgSetParameterfv(colorPaint, VG_PAINT_COLOR, 4, color);
        vgSetPaint(colorPaint, VG_FILL_PATH);
#ifdef OPENVG_VERSION_1_1
        vgSeti(VG_COLOR_TRANSFORM, VG_TRUE);
#endif
        vgDrawImage(m_image);