完成直方图的分段线性变换

basic/urls.py

@@ -15,4 +15,5 @@ urlpatterns = [
     path('flip', views.flip),
     path('affine', views.affine),
     path('histogram', views.histogram),
+    path('plt', views.piecewise_linear_transform),
 ]

basic/views.py

@@ -427,17 +427,66 @@ def histogram(request):
     if request.method == 'POST':
         para = json.loads(request.body)
         image = para['img']
-        img = cv2.imread(PREFIX + image)
+
         color = para['color']
         histogram_name = getImageName() + DEFAULT_FORMAT
         if color:
-            hist_cover_rgb(img, histogram_name)
+            img = cv2.imread(PREFIX + image)
+            hist_cover_rgb(img, PREFIX + histogram_name)
         else:
-            img_gray = cv2.cvtColor(img, cv2.COLOR_RGB2GRAY)
-            hist_cover_gray(img_gray, PREFIX + histogram_name)
+            img = cv2.imread(PREFIX + image, 0)
+            hist_cover_gray(img, PREFIX + histogram_name)
         return HttpResponse(histogram_name)
     return HttpResponse('请使用POST方法')
 
 
+def grayHist(img, filename):
+    plt.figure(filename, figsize=(16, 8))
+    h, w = img.shape[:2]
+    pixelSequence = img.reshape(h * w, 1)
+    numberBins = 256
+    histogram, bins, patch = plt.hist(pixelSequence, numberBins)
+    plt.xlabel("gray label")
+    plt.ylabel("number of pixels")
+    plt.axis([0, 255, 0, np.max(histogram)])
+    # 打印输出峰值
+    plt.savefig(filename)
+
+
+@csrf_exempt
+def piecewise_linear_transform(request):
+    if request.method == 'POST':
+        para = json.loads(request.body)
+        image = para['img']
+        img = cv2.imread(PREFIX + image, 0)
+        funcs = para['func']
+        ret_name1 = getImageName() + DEFAULT_FORMAT
+        ret_name2 = getImageName() + DEFAULT_FORMAT
+        out_name = getImageName() + DEFAULT_FORMAT
+        h, w = img.shape[:2]
+        out = np.zeros(img.shape, np.uint8)
+        for i in range(h):
+            for j in range(w):
+                pix = img[i][j]
+                last_limit = float("-inf")
+                for func in funcs:
+                    limit = func['limit']
+                    k = func['k']
+                    b = func['b']
+                    if limit == -1:
+                        if pix > last_limit:
+                            out[i][j] = k * pix + b
+                    else:
+                        if last_limit <= pix < limit:
+                            out[i][j] = k * pix + b
+                    last_limit = limit
+        out = np.around(out).astype(np.uint8)
+        cv2.imwrite(PREFIX + out_name, out)
+        grayHist(img, PREFIX + ret_name1)
+        grayHist(out, PREFIX + ret_name2)
+        return HttpResponse([{"orig": image, "hist": ret_name1}, {"orig": out_name, "hist": ret_name2}])
+    return HttpResponse('请使用POST方法')
+
+
 def r(request):
     return render(request, 'upload.html')