删除无用图片，增加双线性插值法

main.py

@@ -1,21 +1,24 @@
-from math import floor
+from math import floor, ceil
 from tqdm import tqdm
 
 ################## 数据输入 Start ##################
 
 # 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)："))
-# print("模式 0 直接缩放")
-# print("模式 1 高斯模糊缩放")
+# print("模式 0 双线性插值")
+# print("模式 1 最邻近插值")
+# print("模式 2 高斯模糊缩放")
 # mode = int(input("请输入模式："))
-img = 'imgs/1/2x1.bmp'
-new_width = 512
-new_height = 512
-mode = 0
 
-if (mode != 1):
+img = 'imgs/xjtu.bmp'
+new_width = 256
+new_height = 256
+mode = 1
+
+if (mode not in [0, 1, 2]):
     mode = 0
 
 ################## 数据输入 End ##################
@@ -86,7 +89,7 @@ while (i < len(colorsBoard)):
     })
     i += 4
 
-if (not (bpp in [1, 2, 4, 8, 16, 24, 32])):
+if (not (bpp in [24, 32])):
     print("不支持该图片")
     exit()
 ################## 文件头处理 End ##################
@@ -102,10 +105,22 @@ rowLength = floor(width * bpp / 8)
 while (rowLength % 4 != 0 or rowLength == 0):
     rowLength += 1
 
+# colorsIndex = []
+# if (bpp == 1):
+#     initPixel = imgBytes[dataStart] // 128
+#     colorsIndex.append()
+
 # 计算像素点
 i = dataStart
 for currentRow in tqdm(range(height), "读入像素点中"):
     currentCol = 0
+    # if (bpp in [1, 2, 4, 8]):
+    #     # 其实可以直接存入索引，之后再取出，但是为了易于理解，这里直接将像素数据插入 pixels 数组，这会导致效率的损失
+    #     b = 0
+    #     # while(b < width*bpp):
+    #     #     if(bpp==1):
+    #     #         print("")
+    # else:
     while (currentCol < width * (bpp // 8)):
         if (bpp == 32):
             pixels[currentRow].append({
@@ -126,7 +141,9 @@ for currentRow in tqdm(range(height), "读入像素点中"):
                 'g':
                 imgBytes[dataStart + currentRow * rowLength + currentCol + 1],
                 'b':
-                imgBytes[dataStart + currentRow * rowLength + currentCol + 2]
+                imgBytes[dataStart + currentRow * rowLength + currentCol + 2],
+                'a':
+                0
             })
             currentCol += bpp // 8
 # 读入图片为像素数组完成
@@ -139,11 +156,65 @@ newpixels = []
 for i in range(new_height):
     newpixels.append([])
 
+
+# 辅助计算函数
+def linear_single(x, x1, x2, f1, f2):
+    return floor(f1 * (x2 - x) / (x2 - x1) + f2 * (x - x1) / (x2 - x1))
+
+
+# 双线性插值函数
+# 参考 https://zh.wikipedia.org/wiki/%E5%8F%8C%E7%BA%BF%E6%80%A7%E6%8F%92%E5%80%BC
+def linear_insert(row, col):
+    x = row / scale_h
+    y = col / scale_w
+    # 如果整数格点就直接返回
+    x1 = floor(x)
+    x2 = ceil(x)
+    y1 = floor(y)
+    y2 = ceil(y)
+    if (x2 >= height):
+        x2 = x1
+    if (y2 >= width):
+        y2 = y1
+    if (x1 == x2 and y1 == y2):
+        return pixels[x1][y1]
+    if (x1 == x2):
+        x = x1
+        r = linear_single(y, y1, y2, pixels[x][y1]['r'], pixels[x][y2]['r'])
+        g = linear_single(y, y1, y2, pixels[x][y1]['g'], pixels[x][y2]['g'])
+        b = linear_single(y, y1, y2, pixels[x][y1]['b'], pixels[x][y2]['b'])
+        a = linear_single(y, y1, y2, pixels[x][y1]['a'], pixels[x][y2]['a'])
+        return {'r': r, 'g': g, 'b': b, 'a': a}
+    if (y1 == y2):
+        y = y1
+        r = linear_single(x, x1, x2, pixels[x1][y]['r'], pixels[x2][y]['r'])
+        g = linear_single(x, x1, x2, pixels[x1][y]['g'], pixels[x2][y]['g'])
+        b = linear_single(x, x1, x2, pixels[x1][y]['b'], pixels[x2][y]['b'])
+        a = linear_single(x, x1, x2, pixels[x1][y]['a'], pixels[x2][y]['a'])
+        return {'r': r, 'g': g, 'b': b, 'a': a}
+    fy1_r = linear_single(x, x1, x2, pixels[x1][y1]['r'], pixels[x2][y1]['r'])
+    fy1_g = linear_single(x, x1, x2, pixels[x1][y1]['g'], pixels[x2][y1]['g'])
+    fy1_b = linear_single(x, x1, x2, pixels[x1][y1]['b'], pixels[x2][y1]['b'])
+    fy1_a = linear_single(x, x1, x2, pixels[x1][y1]['a'], pixels[x2][y1]['a'])
+    fy2_r = linear_single(x, x1, x2, pixels[x1][y2]['r'], pixels[x2][y2]['r'])
+    fy2_g = linear_single(x, x1, x2, pixels[x1][y2]['g'], pixels[x2][y2]['g'])
+    fy2_b = linear_single(x, x1, x2, pixels[x1][y2]['b'], pixels[x2][y2]['b'])
+    fy2_a = linear_single(x, x1, x2, pixels[x1][y2]['a'], pixels[x2][y2]['a'])
+    r = linear_single(y, y1, y2, fy1_r, fy2_r)
+    g = linear_single(y, y1, y2, fy1_g, fy2_g)
+    b = linear_single(y, y1, y2, fy1_b, fy2_b)
+    a = linear_single(y, y1, y2, fy1_a, fy2_a)
+    return {'r': r, 'g': g, 'b': b, 'a': a}
+
+
 # 计算新像素
 for currentRow in tqdm(range(new_height), "计算新像素点中"):
     for currentCol in range(new_width):
+        if (mode == 0):
+            newpixels[currentRow].append(linear_insert(currentRow, currentCol))
+        elif (mode == 1):
             ori_row = floor(currentRow / scale_h)
-        ori_col = floor(currentCol // scale_w)
+            ori_col = floor(currentCol / scale_w)
             newpixels[currentRow].append(pixels[ori_row][ori_col])
 
 # 处理新文件
@@ -185,8 +256,21 @@ 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)))
+new_wppm = wppm
+newimgArray.extend(sizeByte(new_wppm, 4))
+
+new_hppm = hppm
+newimgArray.extend(sizeByte(new_hppm, 4))
+
+new_colorsNum = colorsNum
+newimgArray.extend(sizeByte(new_colorsNum, 4))
+
+new_icolorsNum = icolorsNum
+newimgArray.extend(sizeByte(new_icolorsNum, 4))
+
+new_colorsBoard = colorsBoard
+for color in new_colorsBoard:
+    newimgArray.append(color)
 
 
 def flur(row, col):
@@ -244,7 +328,9 @@ def flur(row, col):
 for i in tqdm(range(len(newpixels)), "将像素点格式化中"):
     row = newpixels[i]
     for col in range(len(row)):
-        if (mode == 0):
+        if (mode == 2):
+            newimgArray.extend(flur(i, col))
+        else:
             if (new_bpp // 8 == 3):
                 pixel = [
                     newpixels[i][col]['r'], newpixels[i][col]['g'],
@@ -256,14 +342,12 @@ for i in tqdm(range(len(newpixels)), "将像素点格式化中"):
                     newpixels[i][col]['b'], newpixels[i][col]['a']
                 ]
             newimgArray.extend(pixel)
-        elif (mode == 1):
-            newimgArray.extend(flur(i, col))
     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:
+with open(img[:-4] + "_" + str(mode) +"_new" +  img[-4:], 'wb') as f:
     f.write(newimgBytes)
     for _ in tqdm(range(len(newimgBytes)), "写出图片中"):
         pass