grayscale¶

概要¶

产生内存中数据的灰度图像1

GrayScale [VIDEOTYPE NORMAL|REVERSED] [SCALE v] [ZOOM n]
    [XCROP n1 n2|ON|OFF] [YCROP n1 n2|ON|OFF]

VIDEO NORMAL: 设置 video 类型为 normal。在 Normal 模式中，最小值附近的数据位黑色，最大值附近的数据为白色
VIDEO REVERSED: 设置 video 类型为 reversed。在 Reversed 模式中，最小值附近的数据位白色，最大值附近的数据为黑色
SCALE v: 改变数据的比例因子为v，The data is scaled by raising it to the vth power。小于1的值将平滑图像、降低峰和谷，大于1的值将伸展整个数据
ZOOM n: Image is increased to n times its normal size by pixel replication.
XCROP n1 n2: Turn x cropping option on and change cropping limits to n1 and n2. The limits are in terms of the image size.
XCROP ON: Turn x cropping option on and use previously specified cropping limits.
XCROP OFF: Turn x cropping option off. All of the data in the x direction is displayed.
YCROP n1 n2: Turn y cropping option on and change cropping limits to n1 and n2. The limits are in terms of the image size.
YCROP ON: Turn y cropping option on and use previous specified cropping limits.
YCROP OFF: Turn y cropping option off. All of the data in the y direction is displayed.

grayscale videotype normal scale 1.0 zoom 1 xcrop off ycrop off

这个命令可以用于绘制 spectrogram 命令输出的灰度图，用这个命令显示的 SAC 数据须是“xyz”文件。

注意：SAC 启动了一个脚本来运行图像操作和显示程序，然后再显示 SAC 的提示符。对于大型图像或较慢的机器，这中间会有个明显的延迟。

最大只能显示512*1000

需要：iftype、nxsize、nysize

SAC> getsun: Command not found. （需要Utah Raster Toolkit提供一些工具程序）