如何在tkinter项目中创建保存按钮以保存输出？

Question

我已经创建了tkinter和cv2组合的程序，用于将彩色图像转换为黑白图像，但我不知道如何添加保存黑白图像的按钮。怎么做

# importing the Packages

import cv2  # importing cv2 package for converting the colored imaged to gray or vice versa
import tkinter as tk   # importing tkinter package for creating Gui and its instance io created is tk
from tkinter import filedialog as fd  # importing the filedialog package from tkinter to open the file default file explorer
from PIL import Image, ImageTk    # Python imaginary library for performing operation on images
root = tk.Tk()
root.title("Color to blackNwhite Convertor")
root.config(bg='#FFFAFA')
def selectimage():
    global panelA,panelB   #used two global variables to create two panels
    location = fd.askopenfilename()
    if len(location) > 0:
        image = cv2.imread(location)
        gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
        image = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)
        # convert the images to PIL format...
        image = Image.fromarray(image)
        gray = Image.fromarray(gray)
        # ...and then to ImageTk format
        image = ImageTk.PhotoImage(image)
        gray = ImageTk.PhotoImage(gray)

    if panelA is None or panelB is None:
        panelA = tk.Label(image=image)
        panelA.image = image
        panelA.pack(side="left", padx=10, pady=10)
        panelB = tk.Label(image=gray)
        panelB.image = gray
        panelB.pack(side="right", padx=10, pady=10)
    else:
        panelA.configure(image=image)
        panelB.configure(image=gray)
        panelA.image = image
        panelB.image = gray
panelA = None
panelB = None

btn = tk.Button(root, text="Select an image",font=('arial',10,'bold'),bg="cyan", command=selectimage)
btn.config(height=5,width=15)
btn.pack(side="bottom", fill="both", expand="yes", padx="10", pady="10")
# kick off the GUI
root.mainloop()

Answer 1

您应该保留由Image.fromarray(gray)返回的图像的引用，然后创建一个按钮来触发回调以使用灰色图像上的save()保存灰色图像：

# importing the Packages

import cv2  # importing cv2 package for converting the colored imaged to gray or vice versa
import tkinter as tk   # importing tkinter package for creating Gui and its instance io created is tk
from tkinter import filedialog as fd  # importing the filedialog package from tkinter to open the file default file explorer
from PIL import Image, ImageTk    # Python imaginary library for performing operation on images
root = tk.Tk()
root.title("Color to blackNwhite Convertor")
root.config(bg='#FFFAFA')
def selectimage():
    global panelA,panelB   #used two global variables to create two panels
    global gray_image ### for saving reference to the gray image
    location = fd.askopenfilename()
    if len(location) > 0:
        image = cv2.imread(location)
        gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
        image = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)
        # convert the images to PIL format...
        image = Image.fromarray(image)
        gray_image = Image.fromarray(gray) ### save the gray image
        # ...and then to ImageTk format
        image = ImageTk.PhotoImage(image)
        gray = ImageTk.PhotoImage(gray_image) ### use 'gray_image' instead of 'gray'

    if panelA is None or panelB is None:
        panelA = tk.Label(image=image)
        panelA.image = image
        panelA.pack(side="left", padx=10, pady=10)
        panelB = tk.Label(image=gray)
        panelB.image = gray
        panelB.pack(side="right", padx=10, pady=10)
    else:
        panelA.configure(image=image)
        panelB.configure(image=gray)
        panelA.image = image
        panelB.image = gray

panelA = None
panelB = None
gray_image = None

bframe = tk.Frame(root)
bframe.pack(side="bottom", fill="both", expand="yes")

btn = tk.Button(bframe, text="Select an image",font=('arial',10,'bold'),bg="cyan", command=selectimage)
btn.config(height=5,width=15)
btn.pack(side="left", fill="x", expand=1)

### function to save the gray image
def save_image():
    if gray_image:
        # ask the filename to be used as the output 
        filename = fd.asksaveasfilename()
        if filename:
            gray_image.save(filename) # save the gray image

tk.Button(bframe, text="Save image", font="arial 10 bold", bg="gold", width=15, height=5, command=save_image).pack(side="left", fill="x", expand=1)

# kick off the GUI
root.mainloop()

Answer 2

您可能需要创建postscript文件：

canvas.postscript(file="file_name.ps", colormode='color')

然后使用Pillow将postscript文件保存为png：

from PIL import Image
myImage = Image.open("file_name.ps") 
myImage.save('imageName.png', 'png')