Question

让我解释一下我的意思：我从9张图片中获取数据，包括r，g，b值和亮度，计算每张图片的平均值，然后将每张图片的值写入.txt文件（在记事本中））每张图片的字符串。我现在正试图从该文件中取任意两个字符串，并通过差值公式计算值的差异（差值= val.1 - val.2 / val.2）。我无法弄清楚的是如何读取.txt文件并使用两个不同的字符串进行计算。我非常感谢任何提示或帮助。

这是我到目前为止所拥有的：

from graphics import *


def loadImage(image):
   totalBrightness = 0
   totalR = 0
   totalG = 0
   totalB = 0
   win = GraphWin("Picture", 400, 500)
   testImage = Image(Point(200,250), image)
   testImage.draw(win)
   throwAway = win.getMouse()
   theWidth = testImage.getWidth()
   theHeight = testImage.getHeight()
   for i in range(0,theWidth):
      for j in range(0,theHeight):
          r,g,b = testImage.getPixel(i,j)
          brightness = int(round(0.299*r + 0.587*g + 0.114*b))
          totalR = totalR + r
          totalG = totalG + g
          totalB = totalB + b
          totalBrightness = totalBrightness + brightness
    return (image, totalBrightness, totalR, totalG, totalB)


def ImageAnalysis():
   infile = open("Picture_Features.txt","a+") #cousin told me 'a+' work here if that's important
   print(loadImage("mystery1.GIF"), file = infile)
   print(loadImage("mystery2.GIF"), file = infile)
   print(loadImage("mystery3.GIF"), file = infile)

Answer 1

据我所知，该方法相当简单：

逐行读取并存储为行列表（字符串）
将列表中的所有字符串转换为list / tuple
在列表中选择2个条目并使用差异公式

应该是这样的：

f = open("Picture_Features.txt", 'r')
l = f.readlines()
f.close()

# Convert string to list with split
for i in range(len(l)):
    l[i] = l[i][1:-1].split(', ')

# Let's take the first 2 entries (not the image string in the front)
e1, e2 = map(int, l[0][1:]), map(int, l[1][1:])
diff_formula = lambda x1, x2: (x1 - x2) / x2
result = map(diff_formula, e1, e2)

如何读取文件并使用字符串中的数据计算值？

1 个答案: