指定宽度，高度自适应

名称    处理接口    操作
  
imageMogr2/thumbnail/100x/blur/1x0/quality/100|imageslim
  
imageMogr2/thumbnail/20x/blur/1x0/quality/100|imageslim
  
imageMogr2/thumbnail/30x/blur/1x0/quality/100|imageslim
  
imageMogr2/thumbnail/40x/blur/1x0/quality/100|imageslim
  
imageMogr2/thumbnail/50x/blur/1x0/quality/100|imageslim
  
imageMogr2/thumbnail/60x/blur/1x0/quality/100|imageslim
  
imageMogr2/thumbnail/70x/blur/1x0/quality/100|imageslim
  
imageMogr2/thumbnail/80x/blur/1x0/quality/100|imageslim
  
imageMogr2/thumbnail/90x/blur/1x0/quality/100|imageslim

以此类推都可用