如何导出背景透明的图片？

Question

ClearAll["`*"]
func1[x_, a0_] := x^2 + a0
t1 = Graphics[{Purple, 
    Text[Style[
      "\!\(\*SubscriptBox[\(\[Epsilon]\), \(\[ShortUpArrow]\)]\)(k)", 
      FontFamily -> "Times New Roman", 30], {Pi - 0.5, 1.5}], Red, 
    Text[Style[
      "\!\(\*SubscriptBox[\(\[Epsilon]\), \
\(\[ShortDownArrow]\)]\)(k)", FontFamily -> "Times New Roman", 
      30], {Pi - 1, 11}], Blue, 
    Text[Style["\[Epsilon](k)", FontFamily -> "Times New Roman", 
      30], {0, 2}], Black, 
    Text[Style["\!\(\*SubscriptBox[\(\[Mu]\), \(c\)]\)", 
      FontFamily -> "Times New Roman", 30], {0, 7}], 
    Blend[{Purple, Blue}, 1/2], 
    Text[Style["UM", FontFamily -> "Times New Roman", 
      30], {0, -1}]}];
p1 = Plot[{func1[x, 0], func1[x, 3], func1[x, -3], 8}, {x, -5, 5}, 
   PlotRange -> {{-Pi, Pi}, {-5, 10}}, 
   PlotStyle -> {{Blue}, {Red}, {Purple}, {Dashed, Black}}];
pic = Show[{p1, t1}]
SetDirectory[NotebookDirectory[]];
Export["pic-6.png", pic, ImageResolution -> 200];

怎么让导出的图片背景是透明的？

Answer 1

在 Show 和 Export 中都加上 Background -> None