基本方式完成

.vscode/settings.json

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+{
+    "python.formatting.provider": "yapf"
+}

main.py

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+from math import floor
+
+
+# 十六进制转十进制
+def byteSize(begin, length):
+    size = 0
+    for i in range(length):
+        size += imgBytes[i + begin] * 16**(2 * i)
+    return size
+
+
+# 十进制转十六进制
+def sizeByte(size, length):
+    b = []
+    while (size):
+        b.append(size // 16**((length - len(b) - 1) * 2))
+        size %= 16**((length - len(b)) * 2)
+    b.extend([0] * (length - len(b)))
+    return b[::-1]
+
+
+# 输入数据
+img = input("请输入图片路径：")
+new_width = int(input("请输入新宽度(px)："))
+new_height = int(input("请输入新高度(px)："))
+# img = 'imgs/24.bmp'
+# new_width = 128
+# new_height = 128
+
+# 读入图片
+imgFile = open(img, 'rb')
+imgBytes = imgFile.read()
+
+# 文件头处理
+# 检验文件头是否为 BM
+if (imgBytes[0] != 66 or imgBytes[1] != 77):
+    print("当前文件非 BMP 格式")
+    exit()
+
+fileSize = byteSize(2, 4)  #文件头中的文件大小
+dataStart = byteSize(10, 4)  #文件头中的数据开始字节
+
+# bmp 文件头
+headerSize = byteSize(14, 4)
+width = byteSize(18, 4)
+height = byteSize(22, 4)
+nbplan = byteSize(26, 2)
+bpp = byteSize(28, 2)
+compression = byteSize(30, 4)
+imageSize = byteSize(34, 4)
+# 调色板不做处理
+
+# 变量预处理
+pixels = []
+for i in range(height):
+    pixels.append([])
+rowLength = width
+rowLength *= bpp // 8
+while (rowLength % 4 != 0):
+    rowLength += 1
+
+# 计算像素点
+i = dataStart
+currentRow = 0
+while (currentRow < height):
+    currentCol = 0
+    while (currentCol < width * (bpp // 8)):
+        if (bpp == 32):
+            pixels[currentRow].append({
+                'r':
+                imgBytes[dataStart + currentRow * rowLength + currentCol],
+                'g':
+                imgBytes[dataStart + currentRow * rowLength + currentCol + 1],
+                'b':
+                imgBytes[dataStart + currentRow * rowLength + currentCol + 2],
+                'a':
+                imgBytes[dataStart + currentRow * rowLength + currentCol + 3]
+            })
+            currentCol += bpp // 8
+        else:
+            pixels[currentRow].append({
+                'r':
+                imgBytes[dataStart + currentRow * rowLength + currentCol],
+                'g':
+                imgBytes[dataStart + currentRow * rowLength + currentCol + 1],
+                'b':
+                imgBytes[dataStart + currentRow * rowLength + currentCol + 2]
+            })
+            currentCol += bpp // 8
+    currentRow += 1
+# 读入图片为像素数组完成
+
+# 缩放图片
+# 变量预处理
+scale_w = new_width / width
+scale_h = new_height / height
+newpixels = []
+for i in range(new_height):
+    newpixels.append([])
+
+# 计算新像素
+currentRow = 0
+while (currentRow < new_height):
+    currentCol = 0
+    while (currentCol < new_width):
+        newpixels[currentRow].append(pixels[floor(currentRow / scale_h)][floor(
+            currentCol // scale_w)])
+        currentCol += 1
+    currentRow += 1
+
+# 处理新文件
+newimgArray = [66, 77]
+
+rowLength = new_width
+rowLength *= bpp // 8
+while (rowLength % 4 != 0):
+    rowLength += 1
+
+# 新文件头
+new_fileSize = 54 + rowLength * new_height  #文件头中的文件大小
+newimgArray.extend(sizeByte(new_fileSize, 4))
+
+newimgArray.extend(sizeByte(0, 4))
+
+new_dataStart = dataStart
+newimgArray.extend(sizeByte(new_dataStart, 4))
+
+# 新 bmp 文件头
+new_headerSize = headerSize
+newimgArray.extend(sizeByte(headerSize, 4))
+
+new_width_b = sizeByte(new_width, 4)
+newimgArray.extend(new_width_b)
+
+new_height_b = sizeByte(new_height, 4)
+newimgArray.extend(new_height_b)
+
+new_nbplan = nbplan
+newimgArray.extend(sizeByte(new_nbplan, 2))
+
+new_bpp = bpp
+newimgArray.extend(sizeByte(bpp, 2))
+
+new_compression = compression
+newimgArray.extend(sizeByte(new_compression, 4))
+
+new_imageSize = rowLength * new_height
+newimgArray.extend(sizeByte(new_imageSize, 4))
+
+# 调色板不做处理
+newimgArray.extend(sizeByte(0, new_headerSize + 14 - len(newimgArray)))
+
+for i in range(len(newpixels)):
+    row = newpixels[i]
+    for col in range(len(row)):
+        if (new_bpp // 8 == 3):
+            pixel = [
+                newpixels[i][col]['r'], newpixels[i][col]['g'],
+                newpixels[i][col]['b']
+            ]
+        else:
+            pixel = [
+                newpixels[i][col]['r'], newpixels[i][col]['g'],
+                newpixels[i][col]['b'], newpixels[i][col]['a']
+            ]
+        newimgArray.extend(pixel)
+    newimgArray.extend(sizeByte(0, rowLength - len(row) * (new_bpp // 8)))
+
+# 写入新的文件
+newimgBytes = bytes(newimgArray)
+
+with open(img[:-4] + "_new" + img[-4:], 'wb') as f:
+    f.write(newimgBytes)
+
+# 关闭文件
+imgFile.close()