An application sends a ZIM_GETIMAGEHEIGHT to retrieve the height dimension of the specified image in the ZeeImage image list. The image will be autosized (shrunk) to fit in the client area of the ZeeImage control. This message will return the actual dimensions of the image before any resizing is done by the control to display it.
wParam = (WPARAM)(int) iSlot; //slot or index of the image control
lParam = 0; //Not used. Set to 0.
This message returns the height of the image in pixels, as it was loaded into the ZeeImage control before being displayed.
image_height = SendMessage(himage,ZIM_GETIMAGEHEIGHT,1,0);