Added gen_anchors.py

scripts/gen_anchors.py

@@ -0,0 +1,165 @@
+'''
+Created on Feb 20, 2017
+
+@author: jumabek
+'''
+from os import listdir
+from os.path import isfile, join
+import argparse
+#import cv2
+import numpy as np
+import sys
+import os
+import shutil
+import random 
+import math
+
+width_in_cfg_file = 416.
+height_in_cfg_file = 416.
+
+def IOU(x,centroids):
+    similarities = []
+    k = len(centroids)
+    for centroid in centroids:
+        c_w,c_h = centroid
+        w,h = x
+        if c_w>=w and c_h>=h:
+            similarity = w*h/(c_w*c_h)
+        elif c_w>=w and c_h<=h:
+            similarity = w*c_h/(w*h + (c_w-w)*c_h)
+        elif c_w<=w and c_h>=h:
+            similarity = c_w*h/(w*h + c_w*(c_h-h))
+        else: #means both w,h are bigger than c_w and c_h respectively
+            similarity = (c_w*c_h)/(w*h)
+        similarities.append(similarity) # will become (k,) shape
+    return np.array(similarities) 
+
+def avg_IOU(X,centroids):
+    n,d = X.shape
+    sum = 0.
+    for i in range(X.shape[0]):
+        #note IOU() will return array which contains IoU for each centroid and X[i] // slightly ineffective, but I am too lazy
+        sum+= max(IOU(X[i],centroids)) 
+    return sum/n
+
+def write_anchors_to_file(centroids,X,anchor_file):
+    f = open(anchor_file,'w')
+    
+    anchors = centroids.copy()
+    print(anchors.shape)
+
+    for i in range(anchors.shape[0]):
+        anchors[i][0]*=width_in_cfg_file/32.
+        anchors[i][1]*=height_in_cfg_file/32.
+         
+
+    widths = anchors[:,0]
+    sorted_indices = np.argsort(widths)
+
+    print('Anchors = ', anchors[sorted_indices])
+        
+    for i in sorted_indices[:-1]:
+        f.write('%0.2f,%0.2f, '%(anchors[i,0],anchors[i,1]))
+
+    #there should not be comma after last anchor, that's why
+    f.write('%0.2f,%0.2f\n'%(anchors[sorted_indices[-1:],0],anchors[sorted_indices[-1:],1]))
+    
+    f.write('%f\n'%(avg_IOU(X,centroids)))
+    print()
+
+def kmeans(X,centroids,eps,anchor_file):
+    
+    N = X.shape[0]
+    iterations = 0
+    k,dim = centroids.shape
+    prev_assignments = np.ones(N)*(-1)    
+    iter = 0
+    old_D = np.zeros((N,k))
+
+    while True:
+        D = [] 
+        iter+=1           
+        for i in range(N):
+            d = 1 - IOU(X[i],centroids)
+            D.append(d)
+        D = np.array(D) # D.shape = (N,k)
+        
+        print("iter {}: dists = {}".format(iter,np.sum(np.abs(old_D-D))))
+            
+        #assign samples to centroids 
+        assignments = np.argmin(D,axis=1)
+        
+        if (assignments == prev_assignments).all() :
+            print("Centroids = ",centroids)
+            write_anchors_to_file(centroids,X,anchor_file)
+            return
+
+        #calculate new centroids
+        centroid_sums=np.zeros((k,dim),np.float)
+        for i in range(N):
+            centroid_sums[assignments[i]]+=X[i]        
+        for j in range(k):            
+            centroids[j] = centroid_sums[j]/(np.sum(assignments==j))
+        
+        prev_assignments = assignments.copy()     
+        old_D = D.copy()  
+
+def main(argv):
+    parser = argparse.ArgumentParser()
+    parser.add_argument('-filelist', default = '\\path\\to\\voc\\filelist\\train.txt', 
+                        help='path to filelist\n' )
+    parser.add_argument('-output_dir', default = 'generated_anchors/anchors', type = str, 
+                        help='Output anchor directory\n' )  
+    parser.add_argument('-num_clusters', default = 0, type = int, 
+                        help='number of clusters\n' )  
+
+   
+    args = parser.parse_args()
+    
+    if not os.path.exists(args.output_dir):
+        os.mkdir(args.output_dir)
+
+    f = open(args.filelist)
+  
+    lines = [line.rstrip('\n') for line in f.readlines()]
+    
+    annotation_dims = []
+
+    size = np.zeros((1,1,3))
+    for line in lines:
+                    
+        #line = line.replace('images','labels')
+        #line = line.replace('img1','labels')
+        line = line.replace('JPEGImages','labels')        
+        
+
+        line = line.replace('.jpg','.txt')
+        line = line.replace('.png','.txt')
+        print(line)
+        f2 = open(line)
+        for line in f2.readlines():
+            line = line.rstrip('\n')
+            w,h = line.split(' ')[3:]            
+            #print(w,h)
+            annotation_dims.append(map(float,(w,h)))
+    annotation_dims = np.array(annotation_dims)
+  
+    eps = 0.005
+    
+    if args.num_clusters == 0:
+        for num_clusters in range(1,11): #we make 1 through 10 clusters 
+            anchor_file = join( args.output_dir,'anchors%d.txt'%(num_clusters))
+
+            indices = [ random.randrange(annotation_dims.shape[0]) for i in range(num_clusters)]
+            centroids = annotation_dims[indices]
+            kmeans(annotation_dims,centroids,eps,anchor_file)
+            print('centroids.shape', centroids.shape)
+    else:
+        anchor_file = join( args.output_dir,'anchors%d.txt'%(args.num_clusters))
+        indices = [ random.randrange(annotation_dims.shape[0]) for i in range(args.num_clusters)]
+        centroids = annotation_dims[indices]
+        kmeans(annotation_dims,centroids,eps,anchor_file)
+        print('centroids.shape', centroids.shape)
+
+if __name__=="__main__":
+    main(sys.argv)