Specifies the x coordinate (in layer image coordinates) from which to get the value.
y
The y coordinate (in image coordinates of the layer) to get the value for.
戻り値
Mask image value (0 to 255)
説明
Gets the value (0-255) at an arbitrary position in the layer mask image (image that retains opacity).
Specifying an invalid (out of range) location as an image coordinate will raise an exception.