用来重叠的2张图的尺寸不必考虑,在image函数中设置尺寸即可
fig1='C:\Users\Administrator\Desktop\1.jpg'
fig2='C:\Users\Administrator\Desktop\2.jpg'
fig=image(fig1,dimensions=[500,500],$
image_dimensions=[500,500],position=[0,0,1,1])
fig=image(fig2,dimensions=[500,500],$
transparency=50,$
image_dimensions=[500,500],position=[0,0,1,1],/overplot)