Added stereo evaluation script

Author: asahtik

examples/StereoDepth/read_write_pfm.py

@@ -0,0 +1,65 @@
+import numpy as np
+import re
+import sys
+
+def read_pfm(file):
+    file = open(file, "rb")
+    
+    color = None
+    width = None
+    height = None
+    scale = None
+    endian = None
+
+    header = file.readline().rstrip()
+    if header.decode("ascii") == "PF":
+        color = True    
+    elif header.decode("ascii") == "Pf":
+        color = False
+    else:
+        raise Exception("Not a PFM file.")
+
+    dim_match = re.search(r"(\d+)\s(\d+)", file.readline().decode("ascii"))
+    if dim_match:
+        width, height = map(int, dim_match.groups())
+    else:
+        raise Exception("Malformed PFM header.")
+
+    scale = float(file.readline().rstrip())
+    if scale < 0: # little-endian
+        endian = "<"
+        scale = -scale
+    else:
+        endian = ">" # big-endian
+
+    data = np.fromfile(file, endian + "f")
+    shape = (height, width, 3) if color else (height, width)
+    return np.flip(np.reshape(data, shape), axis=0), scale
+
+def write_pfm(file, image, scale = 1. / 255):
+    image = np.flip(image, axis=0)
+    file = open(file, "wb")
+
+    color = None
+
+    if image.dtype.name != "float32":
+        raise Exception("Image dtype must be float32.")
+
+    if len(image.shape) == 3 and image.shape[2] == 3: # color image
+        color = True
+    elif len(image.shape) == 2 or len(image.shape) == 3 and image.shape[2] == 1: # greyscale
+        color = False
+    else:
+        raise Exception("Image must have H x W x 3, H x W x 1 or H x W dimensions.")
+
+    file.write(b"PF\n" if color else b"Pf\n")
+    file.write(b"%d %d\n" % (image.shape[1], image.shape[0]))
+
+    endian = image.dtype.byteorder
+
+    if endian == "<" or endian == "=" and sys.byteorder == "little":
+        scale = -scale
+
+    file.write(b"%f\n" % scale)
+
+    image.tofile(file)