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python - 在 python 代码中添加一个 forEach 或 for 循环

问题描述

我正在使用这个库midi2img从图像生成 midi

在这个库中，这是正在使用的文件：

from PIL import Image
import numpy as np
from music21 import instrument, note, chord, stream

lowerBoundNote = 21
def column2notes(column):
    notes = []
    for i in range(len(column)):
        if column[i] > 255/2:
            notes.append(i+lowerBoundNote)
    return notes

resolution = 0.25
def updateNotes(newNotes,prevNotes): 
    res = {} 
    for note in newNotes:
        if note in prevNotes:
            res[note] = prevNotes[note] + resolution
        else:
            res[note] = resolution
    return res

def image2midi(image_path):
    with Image.open(image_path) as image:
        im_arr = np.fromstring(image.tobytes(), dtype=np.uint8)
        try:
            im_arr = im_arr.reshape((image.size[1], image.size[0]))
        except:
            im_arr = im_arr.reshape((image.size[1], image.size[0],3))
            im_arr = np.dot(im_arr, [0.33, 0.33, 0.33])

    """ convert the output from the prediction to notes and create a midi file
        from the notes """
    offset = 0
    output_notes = []

    # create note and chord objects based on the values generated by the model

    prev_notes = updateNotes(im_arr.T[0,:],{})
    for column in im_arr.T[1:,:]:
        notes = column2notes(column)
        # pattern is a chord
        notes_in_chord = notes
        old_notes = prev_notes.keys()
        for old_note in old_notes:
            if not old_note in notes_in_chord:
                new_note = note.Note(old_note,quarterLength=prev_notes[old_note])
                new_note.storedInstrument = instrument.Piano()
                if offset - prev_notes[old_note] >= 0:
                    new_note.offset = offset - prev_notes[old_note]
                    output_notes.append(new_note)
                elif offset == 0:
                    new_note.offset = offset
                    output_notes.append(new_note)                    
                else:
                    print(offset,prev_notes[old_note],old_note)

        prev_notes = updateNotes(notes_in_chord,prev_notes)

        # increase offset each iteration so that notes do not stack
        offset += resolution

    for old_note in prev_notes.keys():
        new_note = note.Note(old_note,quarterLength=prev_notes[old_note])
        new_note.storedInstrument = instrument.Piano()
        new_note.offset = offset - prev_notes[old_note]

        output_notes.append(new_note)

    prev_notes = updateNotes(notes_in_chord,prev_notes)

    midi_stream = stream.Stream(output_notes)

    midi_stream.write('midi', fp=image_path.split("/")[-1].replace(".jpeg",".mid"))

import sys
image_path = sys.argv[1]
image2midi(image_path)

这是我在终端中执行以从图像生成 midi 的代码：

python img2midi.py samples/image.png

我需要使上面的代码循环遍历我放在示例文件夹中的所有输入图像，并为每个图像生成 midi，而不是一次只生成一个文件。

任何帮助将非常感激。

标签： pythonmidi

解决方案

您可以通过从目录中获取图像列表并遍历它们来做到这一点。

import sys
import os
sample_folder_path = sys.argv[1]
images = os.listdir(sample_folder_path) # getting all images stored in sample folder
images_path = [os.path.abspath(f"{sample_folder_path}/{image}") for image in images] # gets absolute path for all images
for image_path in images_path:
    image2midi(image_path)

用法：

python img2midi.py folder_path

这folder_path是包含图像的文件夹的路径。它可以

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