This study investigated the spray behavior and atomization characteristics of refrigerant R407C injection in a high pressure chamber under various ambient pressure conditions using a spray visualization system and image processing methods. In order to observe the spray behavior of refrigerant R407C, the spray images were analyzed in time series after the start of injection. From images of spraying features, spray characteristics, for example, the spray tip penetration and cone angle were investigated by using the contour map of the light intensity levels. By using these processes, qualitative properties of refrigerant, when it is discharged from the valve, were quantified.