将处理后的图像数组保存在文件夹中答案

【问题标题】：Saving an array of processed images in a folder将处理后的图像数组保存在文件夹中
【发布时间】：2020-03-11 15:26:39
【问题描述】：

我有这个函数dense_optical_flow 的代码，它的输出是一个数组。该数组的每个元素都是一个图像。如何将这些图像中的每一个保存在一个文件夹中？

%pylab
import cv2
import glob
import matplotlib
import numpy

def dense_optical_flow(images):
    assert len(images) > 1
    ret = []
    pt = 0
    frame1 = cv2.imread(images[pt])
    #print(frame1.shape)
    prvs = cv2.cvtColor(frame1, cv2.COLOR_BGR2GRAY)
    hsv = np.zeros_like(frame1)
    pt += 1
    while (pt != len(images)):
        frame2 = cv2.imread(images[pt])
        next = cv2.cvtColor(frame2, cv2.COLOR_BGR2GRAY)
        flow = cv2.calcOpticalFlowFarneback(prvs, next,None, 0.5, 3, 15, 3, 5, 1.2, 0)
        mag, ang = cv2.cartToPolar(flow[..., 0], flow[..., 1])
        hsv[..., 0] = ang * 180 / np.pi / 2
        hsv[..., 2] = cv2.normalize(mag, None, 0, 255, cv2.NORM_MINMAX)
        rgb = cv2.cvtColor(hsv, cv2.COLOR_HSV2BGR)
        ret.append(rgb)
        prvs = next
        pt += 1
    return np.array(ret)

files = glob.glob("/home/roberto/workspace/TEST/INPUT/intest/*.png")
flist = sorted(files)
plt.imshow(dense_optical_flow(flist)[1]) #this line is just for test!

我已经像这样修改了循环

while (pt != len(images)):
        frame2 = cv2.imread(images[pt])
        next = cv2.cvtColor(frame2, cv2.COLOR_BGR2GRAY)
        flow = cv2.calcOpticalFlowFarneback(prvs, next,None, 0.5, 3, 15, 3, 5, 1.2, 0)
        mag, ang = cv2.cartToPolar(flow[..., 0], flow[..., 1])
        hsv[..., 0] = ang * 180 / np.pi / 2
        hsv[..., 2] = cv2.normalize(mag, None, 0, 255, cv2.NORM_MINMAX)
        rgb = cv2.cvtColor(hsv, cv2.COLOR_HSV2BGR)
        ret.append(rgb)
        prvs = next
        for image in ret:
            filename = '/home/roberto/workspace/TEST/OUTPUT/fbtest/'
            cv2.imwrite(filename + '_TEST' + image +'.npg', image )
        pt += 1
    return np.array(ret)

但它仍然不正确！错误：UFuncTypeError: ufunc 'add' did not contain a loop with signature matching types (dtype('<U48'), dtype('<U48')) -> dtype('<U48')

【问题讨论】：

查看cv2.imwrite
你打错了，是“png”而不是“npg” :)
就像你只会得到最后一张图片 => 你不会在循环中更改名称
是的@Ivan 是对的。我认为它应该是 ``` cv2.imwrite(filename + '_TEST' + image + '.npg', image )``` 但它仍然是错误的！
在循环之前，您可以声明count = 0，然后在循环内count += 1 和filename = '/home/roberto/workspace/TEST/OUTPUT/fbtest/TEST_'+str(count) 这样您将为每个图像使用不同的名称=> 这将在末尾添加一个连续的数字文件名

标签： python arrays image save

【解决方案1】：

正如评论，cv2.imwrite() 应该这样做：

for image in ret:
    filename = xxx ## something that changes in this loop -> you can set a complete path to manage folders
    cv2.imwrite(filename , image )

【讨论】：

请检查我的修改