如何在不复制整个像素图的情况下复制 pyQT QPixmaps 的部分？

Question

我有一个包含图块的图像。我想为 QPixmap 中的每个图块制作一个 QPixmap。我认为 QPixmap 的 copy(x,y,width,height) 方法会为我完成此操作，但必须复制整个图像，而不仅仅是参数定义的矩形，因此会消耗太多内存。

下面的一个例子说明了这个问题。我的 png 恰好是 3400x3078 像素，除以 57 行 50 列，每个 minipixmap 应该是 68x54 像素，但显然使用的内存要多得多。 我错过了什么？

from PyQt5.QtGui import QPixmap
from PyQt5.QtWidgets import QApplication

import os, sys

app = QApplication(sys.argv)
file = r"/path/to/image/grid-of-tiles.png"

# image I'm using has these many rows and columns of tiles
r = 57
c = 50

pixmap = QPixmap(file)

# the tiles are known to divide evenly
width = pixmap.width() / c
height = pixmap.height() / r

# after executing the below, mem use climbs north of 9GB!
# I was expecting on the order of twice the original image's size
minipixmaps = [pixmap.copy(row*height, col*width, width, height) for row in range(r) for col in range(c)]

Answer 1

感谢 eyllanesc 的评论。 QImage 似乎表现得更好：

from PyQt5.QtGui import QPixmap, QImage
from PyQt5.QtWidgets import QApplication

import os, sys

app = QApplication(sys.argv)
file = r"/path/to/image/grid-of-tiles.png"

# image I'm using has these many rows and columns of tiles
r = 57
c = 50

mosaic = QImage(file) # QImage instead of QPixmap

# the tiles are known to divide evenly
width = mosaic.width() / c
height = mosaic.height() / r

# much less memory!
minipixmaps = [QPixmap.fromImage(mosaic.copy(row*height, col*width, width, height)) for row in range(r) for col in range(c)]