有什么简单的方法可以在 tkinter 画布上旋转导入的图像吗？我宁愿不使用 PIL 模块，但我找不到任何可行的替代方案。 （如果有帮助，我想在十字路口转弯时旋转一些汽车图像。）
【问题讨论】：
标签： python-3.x tkinter tkinter-canvas
以下是一种简单但不高效的方法，可将PhotoImage 旋转 90（右）、180 和 270（左）度：
def rotate_image(img, dir):
w, h = img.width(), img.height()
if dir in ['left', 'right']:
newimg = PhotoImage(width=h, height=w)
else: # 180 degree
newimg = PhotoImage(width=w, height=h)
for x in range(w):
for y in range(h):
rgb = '#%02x%02x%02x' % img.get(x, y)
if dir == 'right': # 90 degrees
newimg.put(rgb, (h-y,x))
elif dir == 'left': # -90 or 270 degrees
newimg.put(rgb, (y,w-x))
else: # 180 degrees
newimg.put(rgb, (w-x,h-y))
return newimg
【讨论】：
非常感谢@acw1668 在此页面上的回答，它帮助我开发了这个更有效的解决方案。
事实证明，PhotoImage.put() 方法接受字符串数据，并将在循环中将您提供的任何模式写入字符串，以填充图像中的给定区域。因此，我们不必逐个读取每个像素，然后逐个写入每个像素，而是可以读取每个像素，然后只写入一次！
下面的函数允许您旋转和镜像任何 PhotoImage 对象，并且这样做的时间是逐像素读写方法的一小部分。镜像是通过简单地从后到前读取每一行或每一列来完成的。旋转将每一行写成一列，这实际上将图像旋转了 90 度。
import tkinter as tk
def putToImage(brush, canvas, bbox, mirror_x=False, mirror_y=False, rotate=False):
value1 = brush.height() if rotate else brush.width()
value2 = brush.width() if rotate else brush.height()
start1, end1, increment1 = (value1 - 1, -1, -1) if mirror_x else (0, value1, 1)
start2, end2, increment2 = (value2 - 1, -1, -1) if mirror_y else (0, value2, 1)
data = ""
for col in range(start2, end2, increment2):
data = data + "{"
for row in range(start1, end1, increment1):
data = data + "#%02x%02x%02x " % brush.get(col if rotate else row, row if rotate else col)
data = data + "} "
canvas.put(data, to=bbox)
下面是一个简单的用法示例：
window = tk.Tk()
lbl1 = tk.Label(window)
lbl2 = tk.Label(window)
my_img = tk.PhotoImage(file="my_image.png")
rotated_img = tk.PhotoImage(width=my_img.height(), height=my_img.width())
putToImage(my_img, rotated_img, (0, 0, rotated_img.width(), rotated_img.height()), rotate=True)
lbl1.configure(image=my_img)
lbl1.pack()
lbl2.configure(image=rotated_img)
lbl2.pack()
window.mainloop()
【讨论】：
这是一种在不使用 PIL 模块的情况下使用 tkinter 旋转图像的方法。
所以在我给出答案之前，这里有一些解释。
首先，画布坐标有一个负 y 轴，因此在考虑数学时需要小心这一点。我选择转换为“标准”系统。然后后来我转换回来。不管你做什么，都要小心，因为它很容易混淆。
事实证明（您可以自己拿一张 3x5 的记事卡并在一张纸上旋转来验证这一点），使用对角线测量新的宽度和高度总是足够大以容纳新的旋转图像。
from math import sin, cos, sqrt, pi
from tkinter import *
#returns a rotated PhotoImage
def rotatedPhotoImage(img, angle):
angleInRads = angle * pi / 180
diagonal = sqrt(img.width()**2 + img.height()**2)
xmidpoint = img.width()/2
ymidpoint = img.height()/2
newPhotoImage = PhotoImage(width=int(diagonal), height=int(diagonal))
for x in range(img.width()):
for y in range(img.height()):
# convert to ordinary mathematical coordinates
xnew = float(x)
ynew = float(-y)
# shift to origin
xnew = xnew - xmidpoint
ynew = ynew + ymidpoint
# new rotated variables, rotated around origin (0,0) using simoultaneous assigment
xnew, ynew = xnew*cos(angleInRads) - ynew*sin(angleInRads), xnew * sin(angleInRads) + ynew*cos(angleInRads)
# shift back to quadrant iv (x,-y), but centered in bigger box
xnew = xnew + diagonal/2
ynew = ynew - diagonal/2
# convert to -y coordinates
xnew = xnew
ynew = -ynew
# get pixel data from the pixel being rotated in hex format
rgb = '#%02x%02x%02x' % img.get(x, y)
# put that pixel data into the new image
newPhotoImage.put(rgb, (int(xnew), int(ynew)))
# this helps fill in empty pixels due to rounding issues
newPhotoImage.put(rgb, (int(xnew+1), int(ynew)))
return newPhotoImage
这是用于旋转的函数，例如 34 度。
root = Tk()
mycanvas = Canvas(root, width=300, height=300)
mycanvas.pack()
myPhotoImage=PhotoImage(file="car.png")
myPhotoImage=rotatedPhotoImage(myPhotoImage,34)
canvasImage=mycanvas.create_image(150,150,image=myPhotoImage)
为我转换图像需要 3 秒。
from math import sin, cos, sqrt, pi
from tkinter import *
from time import sleep
def getImageIndex(angle):
# resets 360 to 0
angle = angle % 360
# using 16 images: 360/16 is 22.5 degrees, 11.25 is 1/2 of 22.5
index = (angle-11.25)/22.5 + 1
index = int(index)
index = index % 16
return index
root = Tk()
originalImage = PhotoImage(file="car.png")
carImages = []
for i in range(16): # using 16 images
angle = i*22.5 # 360degrees/16 images = 22.5 degrees
carImages.append(rotatedPhotoImage(originalImage, angle))
mycanvas = Canvas(root, width=300, height=300)
mycanvas.pack()
canvasimage = mycanvas.create_image(150, 150, image=carImages[0], anchor=CENTER)
for i in range(1440): #spins 4 times around
mycanvas.delete(canvasimage)
canvasimage = mycanvas.create_image(150, 150, image=carImages[getImageIndex(i)], anchor=CENTER)
root.update()
sleep(.001)
root.mainloop()
这似乎仅限于使用基本的 tkinter 模块，但是如果您可以通过替换像白色这样的颜色来代替使用 alpha (r,g,b,a)，这里稍微有点该功能的更高级版本，它跳过写入您选择的颜色的像素及其使用示例。
from math import sin, cos, sqrt, pi
from tkinter import *
from time import sleep
# returns a rotated PhotoImage
def rotatedPhotoImage(img, angle, colorToMakeTransparentInHexFormat=""):
angleInRads = angle * pi / 180
diagonal = sqrt(img.width()**2 + img.height()**2)
xmidpoint = img.width()/2
ymidpoint = img.height()/2
newPhotoImage = PhotoImage(width=int(diagonal), height=int(diagonal))
for x in range(img.width()):
for y in range(img.height()):
# convert to ordinary mathematical coordinates
xnew = float(x)
ynew = float(-y)
# shift to origin
xnew = xnew - xmidpoint
ynew = ynew + ymidpoint
# new rotated variables, rotated around origin (0,0) using simoultaneous assigment
xnew, ynew = xnew*cos(angleInRads) - ynew*sin(angleInRads), xnew * sin(angleInRads) + ynew*cos(angleInRads)
# shift back to quadrant iv (x,-y), but centered in bigger box
xnew = xnew + diagonal/2
ynew = ynew - diagonal/2
# convert to -y coordinates
xnew = xnew
ynew = -ynew
# get pixel data from the pixel being rotated in hex format
rgb = '#%02x%02x%02x' % img.get(x, y)
if rgb != colorToMakeTransparentInHexFormat:
# put that pixel data into the new image
newPhotoImage.put(rgb, (int(xnew), int(ynew)))
# this helps fill in empty pixels due to rounding issues
newPhotoImage.put(rgb, (int(xnew+1), int(ynew)))
return newPhotoImage
def getImageIndex(angle):
# resets 360 to 0
angle = angle % 360
# using 16 images: 360/16 is 22.5 degrees, 11.25 is 1/2 of 22.5
index = (angle-11.25)/22.5 + 1
index = int(index)
index = index % 16
return index
root = Tk()
originalImage = PhotoImage(file="carwhitebg.png")
carImages = []
for i in range(16): # using 16 images
angle = i*22.5 # 360degrees/16 images = 22.5 degrees
carImages.append(rotatedPhotoImage(originalImage, angle,"#ffffff"))
mycanvas = Canvas(root, width=300, height=300,bg="orange")
mycanvas.pack()
canvasimage = mycanvas.create_image(150, 150, image=carImages[0], anchor=CENTER)
for i in range(943): #some arbitrary number of degrees
mycanvas.delete(canvasimage)
canvasimage = mycanvas.create_image(150, 150, image=carImages[getImageIndex(i)], anchor=CENTER)
root.update()
sleep(.001)
root.mainloop()
【讨论】：