Do auto level without photoshop -> 속도 개선 성공 :)

import Image
 
def getMinMax(histo,threshHold = 0):
    minV = 0
    maxV = 0
    for i in range(0,256):
        if sum(histo[:i+1]) > threshHold:
            minV = i
            break
    for i in range(255,0,-1):
        if sum(histo[i:]) > threshHold:
            maxV = i
            break
    print 'minV, maxV :', minV, maxV
    return minV, maxV
 
def getAutoLevel(minV, maxV, data):
    result = ((data-minV)*255)/(maxV-minV)
    return result #return int(round(result))
 
def autoLevel(imgName, outName = None, threshold = 0):
    if not outName:
        outName = imgName
 
    img = Image.open(imgName)
    data = img.getdata()
 
    ## Set threshold ##
    if threshold == 0: #auto threshold "0.5%"
        threshold = (len(data)*0.5)/100
        print 'auto threshold %d'%threshold
 
    ## Find cutting point ##
    histo = img.histogram()
    minR,maxR = getMinMax(histo[:256],threshold)
    minG,maxG = getMinMax(histo[256:256*2],threshold)
    minB,maxB = getMinMax(histo[256*2:],threshold)
 
    ## Create new image ##
    #print outName, 
    imgNew = Image.new('RGB',img.size)   
    width = img.size[0]
    x = 0
    y = 0
    for i in range(len(data)):  # <- 아 여기 너무 느려요 T-T
        r,g,b = data[i]
        r = getAutoLevel(minR, maxR, r)
        g = getAutoLevel(minG, maxG, g)
        b = getAutoLevel(minB, maxB, b)
        imgNew.putpixel((x,y),(r,g,b))
        x += 1
        if x >= width:
            x = 0
            y+=1
    #print len(data)
    imgNew.save(outName)
    return
 
def __test_1():
    import glob
    import os
    import time
    dirName = r'D:\Image\'
    for f in glob.glob(os.path.join(dirName,'*.jpg')):
        print f
        if not os.path.isfile(f):
            print '##',
            print f
            continue	
        s = time.time()
        autoLevel(f)
        e = time.time()
        print 'it takes %d secs\n'%int(e-s)
 
 
# test function #
if __name__ == '__main__':
    __test_1()

def autoLevel(imgName, outName = None, threshold = 0):
    if not outName:
        outName = imgName
 
    img = Image.open(imgName)
    data = img.getdata()
 
    ## Set threshold ##
    if threshold == 0: #auto threshold "1%"
        threshold = (len(data)*0.5)/100
        print 'auto threshold %d'%threshold
 
    ## Find cutting point ##
    histo = img.histogram()
    minR,maxR = getMinMax(histo[:256],threshold)
    minG,maxG = getMinMax(histo[256:256*2],threshold)
    minB,maxB = getMinMax(histo[256*2:],threshold)
 
    ## Create new image ##
    rgb2al_rgb = (
        (255.0/(maxR-minR)), 0.0, 0.0, -((255.0*minR)/(maxR-minR)),
        0.0, (255.0/(maxG-minG)), 0.0, -((255.0*minG)/(maxG-minG)),
        0.0, 0.0, (255.0/(maxB-minB)), -((255.0*minB)/(maxB-minB)) )
    imgNew = img.convert("RGB", rgb2al_rgb)
    imgNew.save(outName)
    return