要以恒定的长宽比缩放矩形，请按下 "Shift "键。
图用于定义 "感兴趣区"（ROI）的矩形形状
减法矩形 ROI 绘制工具
减法矩形 ROI 绘图工具的操作方法与加法矩形 ROI 绘图工具相同，但区域定义为 "非感兴趣区"。
有关处理减法绘图工具的信息，另请参阅 ROI 工具的应用顺序。
Rectangular ROI tool. This can be rotated, scaled and moved.
To scale the rectangle with constant aspect ratio, press the "Shift" key.
Fig.: Rectangular shape for defining a "region of interest" (ROI)
Subtractive rectangle ROI drawing tool
The subtractive rectangle ROI drawing tool can be manipulated in the same way as the additive one, but the area is defined as "not of interest".
For information about handling subtractive drawing tools, see also Order of application for ROI tools.