Python利用自带模块实现屏幕像素高效操作

1、获取屏幕放缩比例

from ctypes import wintypesimport ctypes  HORZRES = 8LOGPIXELSX = 118  def get_scale_factor() -> float:    user32 = ctypes.windll.user32    gdi32 = ctypes.windll.gdi32     # 定义 HDC 和 UINT 类型    HDC = wintypes.HDC    UINT = wintypes.UINT     # 定义 GetDC 和 GetDeviceCaps 的参数类型和返回类型    user32.GetDC.argtypes = [wintypes.HWND]    user32.GetDC.restype = HDC     gdi32.GetDeviceCaps.argtypes = [HDC, UINT]    gdi32.GetDeviceCaps.restype = wintypes.INT     # 获取设备上下文    dc = user32.GetDC(None)    widthScale = gdi32.GetDeviceCaps(dc, HORZRES)    width = gdi32.GetDeviceCaps(dc, LOGPIXELSX)    scale = width / widthScale    return scale

2、获取屏幕指定坐标处像素颜色

import ctypesfrom ctypes import wintypesfrom typing import Sequence, Generator  user32 = ctypes.windll.user32gdi32 = ctypes.windll.gdi32 # 定义类型HWND = wintypes.HWNDHDC = wintypes.HDCHBITMAP = wintypes.HBITMAP  class BITMAPINFOHEADER(ctypes.Structure):    _fields_ = [        ("biSize", wintypes.DWORD),        ("biWidth", wintypes.LONG),        ("biHeight", wintypes.LONG),        ("biPlanes", wintypes.WORD),        ("biBitCount", wintypes.WORD),        ("biCompression", wintypes.DWORD),        ("biSizeImage", wintypes.DWORD),        ("biXPelsPerMeter", wintypes.LONG),        ("biYPelsPerMeter", wintypes.LONG),        ("biClrUsed", wintypes.DWORD),        ("biClrImportant", wintypes.DWORD)    ] class BITMAPINFO(ctypes.Structure):    _fields_ = [        ("bmiHeader", BITMAPINFOHEADER),        ("bmiColors", wintypes.DWORD * 3)    ]  def get_pixel_color(coords: Sequence[tuple[int, int]], hwnd: HWND) -> Generator[tuple[int, int, int], None, None]:    rect = wintypes.RECT()    user32.GetClientRect(hwnd, ctypes.byref(rect))    width = rect.right - rect.left    height = rect.bottom - rect.top     # 创建内存设备上下文    hdc_src = user32.GetDC(hwnd)    hdc_dst = gdi32.CreateCompatibleDC(hdc_src)    bmp = gdi32.CreateCompatibleBitmap(hdc_src, width, height)    gdi32.SelectObject(hdc_dst, bmp)     # 使用 BitBlt 复制窗口内容到内存设备上下文    gdi32.BitBlt(hdc_dst, 0, 0, width, height, hdc_src, 0, 0, 0x00CC0020)  # SRCCOPY     # 获取位图信息    bmi = BITMAPINFO()    bmi.bmiHeader.biSize = ctypes.sizeof(BITMAPINFOHEADER)    bmi.bmiHeader.biWidth = width    bmi.bmiHeader.biHeight = -height  # 负值表示自底向上    bmi.bmiHeader.biPlanes = 1    bmi.bmiHeader.biBitCount = 32    bmi.bmiHeader.biCompression = 0     # 创建缓冲区并获取位图数据    buffer = ctypes.create_string_buffer(width * height * 4)    gdi32.GetDIBits(hdc_dst, bmp, 0, height, buffer, ctypes.byref(bmi), 0)     # 释放资源    gdi32.DeleteObject(bmp)    gdi32.DeleteDC(hdc_dst)    user32.ReleaseDC(hwnd, hdc_src)     # 遍历指定坐标并返回像素颜色    for x, y in coords:        if 0 <= x < width and 0 <= y < height:            offset = (y * width + x) * 4            color = buffer[offset:offset + 4]            yield color[2], color[1], color[0]  # BGR -> RGB        else:            yield (0, 0, 0)

3、一个简单的使用案例

from typing import Sequence, Generator, Tuplefrom tkinter import ttkimport tkinter as tkfrom ctypes import wintypesimport ctypesimport requestsfrom io import BytesIOfrom PIL import Image, ImageTk     user32 = ctypes.windll.user32gdi32 = ctypes.windll.gdi32 HWND = wintypes.HWNDHDC = wintypes.HDCHBITMAP = wintypes.HBITMAP  class BITMAPINFOHEADER(ctypes.Structure):    _fields_ = [        ("biSize", wintypes.DWORD),        ("biWidth", wintypes.LONG),        ("biHeight", wintypes.LONG),        ("biPlanes", wintypes.WORD),        ("biBitCount", wintypes.WORD),        ("biCompression", wintypes.DWORD),        ("biSizeImage", wintypes.DWORD),        ("biXPelsPerMeter", wintypes.LONG),        ("biYPelsPerMeter", wintypes.LONG),        ("biClrUsed", wintypes.DWORD),        ("biClrImportant", wintypes.DWORD)    ]  class BITMAPINFO(ctypes.Structure):    _fields_ = [        ("bmiHeader", BITMAPINFOHEADER),        ("bmiColors", wintypes.DWORD * 3)    ]  def get_pixel_color(coords: Sequence[Tuple[int, int]], hwnd: HWND) -> Generator[Tuple[int, int, int], None, None]:    rect = wintypes.RECT()    user32.GetClientRect(hwnd, ctypes.byref(rect))    width = rect.right - rect.left    height = rect.bottom - rect.top     hdc_src = user32.GetDC(hwnd)    hdc_dst = gdi32.CreateCompatibleDC(hdc_src)    bmp = gdi32.CreateCompatibleBitmap(hdc_src, width, height)    gdi32.SelectObject(hdc_dst, bmp)     gdi32.BitBlt(hdc_dst, 0, 0, width, height, hdc_src, 0, 0, 0x00CC0020)  # SRCCOPY     bmi = BITMAPINFO()    bmi.bmiHeader.biSize = ctypes.sizeof(BITMAPINFOHEADER)    bmi.bmiHeader.biWidth = width    bmi.bmiHeader.biHeight = -height  # 负值表示自底向上    bmi.bmiHeader.biPlanes = 1    bmi.bmiHeader.biBitCount = 32    bmi.bmiHeader.biCompression = 0     buffer = ctypes.create_string_buffer(width * height * 4)    gdi32.GetDIBits(hdc_dst, bmp, 0, height, buffer, ctypes.byref(bmi), 0)     gdi32.DeleteObject(bmp)    gdi32.DeleteDC(hdc_dst)    user32.ReleaseDC(hwnd, hdc_src)     for x, y in coords:        print(x, y, width, height)        if 0 <= x < width and 0 <= y < height:            offset = (y * width + x) * 4            color = buffer[offset:offset + 4]            yield color[2], color[1], color[0]  # BGR -> RGB        else:            yield (0, 0, 0)  def get_window_handle(window):    window_name = window._w    if not window_name.startswith("."):        window_name = "." + window_name        hwnd = ctypes.windll.user32.FindWindowW(None, window.title())    if not hwnd:        raise ValueError("Cannot get the window handle.")    return hwnd def download_image(url):    response = requests.get(url)    if response.status_code == 200:        return Image.open(BytesIO(response.content))    else:        raise Exception(f"Failed to download image: HTTP {response.status_code}") def display_image_in_label(image):    photo = ImageTk.PhotoImage(image)    label = ttk.Label(root, image=photo)    label.image = photo  # 保持对 PhotoImage 的引用，防止被垃圾回收    label.pack()  def show_color(event):    hwnd = get_window_handle(root)    x, y = event.x, event.y    # 注意这里的坐标是相对于窗口的坐标，且传入get_pixel_color的应该是包含多个坐标点的序列    # 此外，为了高效获取同一个画面多个点的颜色，此处我使用了生成器进行懒加载，因此获取数据时请完整遍历迭代器    result = get_pixel_color([(x, y)], hwnd)    colors = [i for i in result]    print(f"{event.x, event.y}: {colors}")  if __name__ == "__main__":    root = tk.Tk()    width, height = 900, 500    screenwidth = root.winfo_screenwidth()    screenheight = root.winfo_screenheight()    geometry = '%dx%d+%d+%d' % (width, height, (screenwidth - width) / 2, (screenheight - height) / 2)    root.title("测试样例")    root.geometry(geometry)    root.bind("<Motion>", show_color)     image_url = "http://www.txwjcyj.com/zb_users/upload/php/zumimevmaqm72.jpg&ehk=9NnCJ9JG44zfdF2%2fr373s25s68H9vxLvyfMsKgEzAwc%3d&risl=&pid=ImgRaw&r=0"    try:        img = download_image(image_url)        display_image_in_label(img)    except Exception as e:        print(f"Error: {e}")        ttk.Label(root, text="Failed to load image.").pack()     root.mainloop()