FUNCTION LINEAR2, inImage,inPer

  COMPILE_OPT idl2

  ;

  IF N_ELEMENTS(inPer) EQ 0 THEN inPer = 0.02

  sz = SIZE(inImage)

  ;图像太大的话统计太慢，模仿ENVI，仅对Scroll窗口进行统计，默认大小是256*256

  IF sz[0] EQ 2 THEN BEGIN

    image = CONGRID(inImage, 256, 256)

  ENDIF ELSE BEGIN

    image = CONGRID(inImage, sz[1], 256, 256)

  ENDELSE

  ;图像基本信息

  sz = SIZE(image)

  IF sz[0] EQ 2 THEN BEGIN

    nPlanes = 1

    x = sz[1]

    y = sz[2]

  ENDIF ELSE BEGIN

    nPlanes = 3

    x = sz[2]

    y = sz[3]

  ENDELSE

  outImage = inImage

  FOR i=0, nPlanes-1 DO BEGIN

    IF nPlanes EQ 3 THEN img = REFORM(image[i,*,*]) ELSE img=image

    ;直方图统计

    array = HISTOGRAM(img,oMax = maxV,oMin = minV)

    arrnumb= N_ELEMENTS(array)

    ;

    percent = TOTAL(array,/CUMULATIVE)/TOTAL(array)

    idx1 = WHERE(percent LE inPer)

    idx2 = WHERE(percent GE inPer)

    number = N_ELEMENTS(idx1)

    ;计算当前inpert对应的数值 （2%）

    ;两个索引，取临近索引

    curIdx = (ABS(percent[idx1[number-1]]-inPer) LE ABS(percent[idx2[0]]-inPer))? idx1[number-1]:idx2[0]

    minvalue = minV +(maxV-minV)*curIdx/(arrnumb-1)

    ;1-inper对应数值 （98%）

    idx1 = WHERE(percent LE (1-inPer))

    idx2 = WHERE(percent GE (1-inPer))

    number = N_ELEMENTS(idx1)

    ;两个索引，取临近索引

    curIdx = (ABS(percent[idx1[number-1]]-1+inPer) LE ABS(percent[idx2[0]]-1+inPer))? idx1[number-1]:idx2[0]

    maxvalue = minV +(maxV-minV)*curIdx/(arrnumb-1)

    ;单波段还是多波段

    IF nPlanes EQ 3 THEN $

      outImage[i,*,*] = BYTSCL(outImage[i,*,*], max=maxvalue, min=minvalue) $

    ELSE outImage = BYTSCL(outImage, max=maxvalue, min=minvalue)

  ENDFOR

  IF nPlanes EQ 1 THEN outImage = REFORM(outImage)

  RETURN, outImage

END