如何从带有图像注释的CSV文件中提取值，并将它们附加到新的RetinaNet文件中？

Question

我正在尝试将软件中的csv文件转换为一个可以在RetinaNet中使用的csv文件。RetinaNet培训数据所需的格式是:path/to/Image.jpg、x1、y1、x2、y2、class_name。这是我的CSV文件的一个例子，它来自于VIA：+=============+===========+==============+===========+========================================================+===+、file_size、filename、file_size、region_count、region_id、region_shape_attributes、、、img 30.png、2331731、10、10、10，{"name":"rect"，"x":65，"y":778，“宽度”：108，“高度”：65}\x{e76f} +-------------+-----------+--------------+-----------+--------------------------------------------------------+---+

基本上，我需要从括号中提取x、y、宽度和高度属性，并将它们附加到列表中。这是我的python代码：

import csv

via_path = 'data/tiled/via.csv'

image_annotations = []

with open(via_path, "r") as f:
    reader = csv.reader(f, delimiter=",")
    for line in reader: 
        if '#' in line[0][0]:
            # bypassing comments in csv
            continue
        filename = line[1][2:-2]
        # strip brackets, split and get only the values we care about, then convert all the string to int 
        top_left_x, top_left_y, width, height = list(map(int,list(map(float, line[4].strip('][').split(',')[1:]))))

        if width == 0 or height == 0:
            continue

        # move from top left and width/height to x and y values
        if top_left_x < 0:
            top_left_x = 1
        if top_left_y < 0:
            top_left_y = 1
        x1 = top_left_x
        x2 = top_left_x + width
        y1 = top_left_y
        y2 = top_left_y + height 

        # TODO didn't add names this time since it is all one class
        name = "bird"

        # create the csv row
        new_row = []
        new_row.append(filename)
        new_row.append(x1)
        new_row.append(y1)
        new_row.append(x2)
        new_row.append(y2)
        new_row.append(name)

        image_annotations.append(new_row)

该代码输出：

ValueError
---> top_left_x, top_left_y, width, height = list(map(int,list(map(float, line[4].strip('][').split(',')[1:]))))
ValueError: not enough values to unpack (expected 4, got 0)

Answer 1

region_shape_attributes列是一个JSON字符串。您需要解析它，以获得它包含的值。

Python内置了JSON支持：

import json

# ... open CSV file, for each record ...

    shape = json.parse(line[4])

    top_left_x = shape['x']
    top_left_y = shape['y']
    # etc