Android. 9png

Explanation: the area of the black strip at the position of the First Part indicates that only the area is stretched when the image is horizontally stretched.
The area to the right of the black bar 2 indicates that only the area is stretched when the image is stretched vertically.
The position of the black bar 3 is left-covered, indicating the area where the image is displayed vertically.
The area to which the black bar on the 4th is overwritten indicates the area where the image is horizontally displayed.
The area where the image is not covered by black bars remains unchanged when it is stretched (for example, if the four corners of the image are curved, when the image is stretched randomly, the arc shapes of the four corners will not change)