用ChatGPT写的垃圾性能图片查看器，在标题栏显示ev100值 #vibecoding #photography #image

a.py

import os
import sys
import tkinter as tk
from tkinter import Label, messagebox
from PIL import Image, ImageTk
import piexif

class ImageViewer:
    def _on_mousewheel(self, event):
        # Windows/macOS: event.delta positive = up, negative = down
        # Linux: Button-4 = up, Button-5 = down
        delta = 0
        if hasattr(event, 'delta') and event.delta != 0:
            delta = event.delta
        else:
            if event.num == 4:
                delta = 1
            elif event.num == 5:
                delta = -1

        if delta > 0:
            self.prev_image()
        else:
            self.next_image()


    def __init__(self, root, target_path):
        self.root = root
        self.target_path = target_path

        # Gather files (non-recursive), sort them, then decide which one to show
        if os.path.isdir(target_path):
            folder = target_path
            files = [f for f in os.listdir(folder) if f.lower().endswith('.jpg')]
            files.sort()
            if not files:
                messagebox.showerror("错误", f"目录 {folder} 中没有找到 jpg 文件")
                root.destroy()
                return
            self.files = files
            self.folder = folder
            self.index = 0  # 目录输入时显示排序后的第一个
        else:
            folder = os.path.dirname(target_path) or '.'
            files = [f for f in os.listdir(folder) if f.lower().endswith('.jpg')]
            files.sort()
            if not files:
                messagebox.showerror("错误", f"{folder} 中没有找到 jpg 文件")
                root.destroy()
                return
            basename = os.path.basename(target_path)
            if basename not in files:
                # 传入的文件不是 jpg 或不在同一目录的文件列表内
                messagebox.showwarning("警告", f"指定文件 {basename} 未在目录 {folder} 的 jpg 列表中，默认使用第一个文件")
                self.index = 0
            else:
                self.index = files.index(basename)

            self.files = files
            self.folder = folder

        # 窗口尺寸为屏幕大小的一半
        screen_w = root.winfo_screenwidth()
        screen_h = root.winfo_screenheight()
        root.geometry(f"{screen_w//2}x{screen_h//2}")

        self.label = Label(root)
        self.label.pack(fill=tk.BOTH, expand=True)

        root.bind('<Left>', lambda e: self.prev_image())
        root.bind('<Right>', lambda e: self.next_image())
        root.bind('<Configure>', lambda e: self._on_configure())
        root.bind('q', lambda e: root.destroy())
        root.bind('<MouseWheel>', lambda e: self._on_mousewheel(e))  # Windows/macOS
        root.bind('<Button-4>', lambda e: self._on_mousewheel(e))    # Linux scroll up
        root.bind('<Button-5>', lambda e: self._on_mousewheel(e))    # Linux scroll down


        self.original_img = None
        self.exif = {}
        self.tk_img = None

        self.show_image()

    def load_image(self):
        path = os.path.join(self.folder, self.files[self.index])
        try:
            self.original_img = Image.open(path)
            try:
                self.exif = piexif.load(path)
            except Exception:
                self.exif = {}
        except Exception as e:
            messagebox.showerror("错误", f"不能打开图片: {path} {e}")
            self.original_img = None
            self.exif = {}
        except Exception as e:
            messagebox.showerror("错误", f"不能打开图片: {path}\n{e}")
            self.original_img = None
            self.exif = {}

    def compute_ev100(self):
        try:
            if not self.exif or "Exif" not in self.exif:
                return "N/A"
            ex = self.exif["Exif"]

            def to_float(v):
                try:
                    if isinstance(v, tuple) and len(v) == 2:
                        num, den = v
                        return num / den if den else None
                    return float(v)
                except:
                    return None

            t = to_float(ex.get(piexif.ExifIFD.ExposureTime))
            n = to_float(ex.get(piexif.ExifIFD.FNumber))
            iso = ex.get(piexif.ExifIFD.ISOSpeedRatings)
            if isinstance(iso, (list, tuple)):
                iso = iso[0]
            try:
                iso = float(iso)
            except:
                iso = None

            if not t or not n or not iso or t <= 0 or iso <= 0:
                return "N/A"

            import math
            ev100 = math.log2((n * n) / t) - math.log2(iso / 100.0)
            return f"{ev100:.2f}"
        except Exception:
            return "N/A"

            # EXIF tags (numeric): 33434 ExposureTime, 33437 FNumber, 34855 ISOSpeedRatings
            t = exif.get(33434)
            n = exif.get(33437)
            iso = exif.get(34855)

            # EXIF values sometimes are rational tuples
            def to_float(v):
                if v is None:
                    return None
                if isinstance(v, tuple) and len(v) == 2 and v[1] != 0:
                    return float(v[0]) / float(v[1])
                try:
                    return float(v)
                except Exception:
                    return None

            t = to_float(t)
            n = to_float(n)
            iso = to_float(iso)

            if t is None or n is None or iso is None or t <= 0 or iso <= 0:
                return "N/A"

            import math
            ev100 = math.log2((n * n) / t) - math.log2(iso / 100.0)
            return f"{ev100:.2f}"
        except Exception:
            return "N/A"

    def update_title(self):
        name = self.files[self.index]
        ev = self.compute_ev100()
        self.root.title(f"{self.index+1}/{len(self.files)}  {name}  EV100={ev}")

    def show_image(self):
        self.load_image()
        self.update_title()
        self.resize_image()

    def resize_image(self):
        if self.original_img is None:
            return
        # 获取当前可用显示区域
        w = self.label.winfo_width()
        h = self.label.winfo_height()
        if w < 10 or h < 10:
            return

        # 按比例缩放，使图片完全适应区域（letterbox），保持长宽比
        img = self.original_img.copy()
        img_ratio = img.width / img.height
        area_ratio = w / h

        if img_ratio > area_ratio:
            # 以宽度为准
            new_w = w
            new_h = int(w / img_ratio)
        else:
            # 以高度为准
            new_h = h
            new_w = int(h * img_ratio)

        img = img.resize((max(1, new_w), max(1, new_h)), Image.LANCZOS)
        self.tk_img = ImageTk.PhotoImage(img)
        self.label.config(image=self.tk_img)

    def _on_configure(self):
        # 窗口大小改变时更新图片显示和标题（标题里也显示当前图片索引）
        self.resize_image()
        self.update_title()

    def prev_image(self):
        if not self.files:
            return
        self.index = (self.index - 1) % len(self.files)
        self.show_image()

    def next_image(self):
        if not self.files:
            return
        self.index = (self.index + 1) % len(self.files)
        self.show_image()


if __name__ == '__main__':
    root = tk.Tk()
    target_path = sys.argv[1] if len(sys.argv) > 1 else '.'
    viewer = ImageViewer(root, target_path)
    # 如果初始化失败（例如没有图片），ImageViewer 会调用 root.destroy()
    try:
        root.mainloop()
    except Exception:
        pass