全新的scipy / numpy并尝试一些批量操作

Question

所以，我有一堆扫描的图像，周围有恼人的白色，我想删除。我正在准备一个使用numpy数组的算法来找到最接近的完整白色像素行和列，将它们裁剪到那些位置。这是我的代码：

from scipy import misc
import os
import datetime

a0 = datetime.datetime.now()
print("Imported at " + str(a0))

def run():
    inputdir = '/Users/nicholasezyk/Documents/funeralhomescans'
    os.chdir(inputdir)

    #batch image renaming
    counter = 1
    for file in os.listdir(inputdir):
        if file.endswith('.jpg'):
            img = misc.imread(file)
            print(file + ' being analyzed.')
            cropx = -1
            cropy = -1
            lx = img.shape[0]
            ly = img.shape[1]
            countx = 0
            county = 0
            while countx < lx:
                pix = img[countx, 0]
                if pix == (255, 255, 255):
                    tempcountx = 1
                    scorex = 1
                    while tempcountx < ly:
                        if img[countx, tempcountx] == (255, 255, 255):
                            scorex = scorex + 1
                        tempcountx = tempcountx + 1
                    if 1000 * (scorex / ly) > 1000:
                        cropx = tempcountx
                        break
            while county < ly:
                pix = img[0, county]
                if pix == (255, 255, 255):
                    tempcounty = 1
                    scorey = 1
                    while tempcounty < lx:
                        if img[tempcounty, county] == 255:
                            scorey = scorey + 1
                        tempcounty = tempcounty + 1
                    if 1000 * (scorey / lx) == 1000:
                        cropy = tempcounty
                        break
            send = img[0:cropx, 0:cropy]
            misc.imsave('crop' + str(counter) + '.png', send)
            print(file + ' cropped and exported as ' + 'crop' + str(counter) + '.png')

run()

现在，这是我的控制台声明：

Imported at 2014-10-04 15:12:32.237369
test.jpg being analyzed.
Traceback (most recent call last):
  File "/Users/nicholasezyk/Documents/whiteout.py", line 52, in <module>
    run()
  File "/Users/nicholasezyk/Documents/whiteout.py", line 26, in run
    if pix == (255, 255, 255):
ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

由于我不熟悉语法，如果有人能帮我弄清楚如何使用numpy数组，那就太棒了。