Monthly Archives: October 2010

Oct 5 2010

Converting Python to exe (windows)

If you “google”, first link you might come across (http://www.py2exe.org/) itself would guide you.

By shrex999
0
Oct 4 2010

Python Imaging Library – YUV NV12 viewer

Powerful imaging tool with Python. I was fascinated with this.

http://www.pythonware.com/products/pil/

– I wrote a small program to read YUV NV12 image and display it using default image viewer in Windows XP. Same time a BMP file also written in to the local disk.

YUV NV12 : http://www.fourcc.org/yuv.php#NV12




# Author : sherin.s@gmail.com (Sherin Sasidhan)
# Date   : 05-Oct-2010

import Image
import sys
from struct import *
import array

if len(sys.argv) != 5:
        print "***** Usage syntax Error!!!! *****\n"
        print "Usage:"
        print "python display-image.py <.yuv file NV12 format> <width> <height> <'nv12'> "
        sys.exit(1) # exit
else:
        pass

image_name = sys.argv[1]
width = int(sys.argv[2])
height = int(sys.argv[3])
format = sys.argv[4]
y = array.array('B')
u = array.array('B')
v = array.array('B')

f_y = open(image_name, "rb")
f_uv = open(image_name, "rb")
f_uv.seek(width*height, 1)

image_out = Image.new("RGB", (width, height))
pix = image_out.load()

print "width=", width, "height=", height

for i in range(0, height/2):
	for j in range(0, width/2):
		u.append(ord(f_uv.read(1)));
		v.append(ord(f_uv.read(1)));

for i in range(0,height):
	for j in range(0, width):
		y.append(ord(f_y.read(1)));
		#print "i=", i, "j=", j , (i*width), ((i*width) +j)
		#pix[j, i] = y[(i*width) +j], y[(i*width) +j], y[(i*width) +j]
		Y_val = y[(i*width)+j]
		U_val = u[((i/2)*(width/2))+(j/2)]
		V_val = v[((i/2)*(width/2))+(j/2)]
		B = 1.164 * (Y_val-16) + 2.018 * (U_val - 128)
		G = 1.164 * (Y_val-16) - 0.813 * (V_val - 128) - 0.391 * (U_val - 128)
		R = 1.164 * (Y_val-16) + 1.596*(V_val - 128)
		pix[j, i] = int(R), int(G), int(B) # update 31/07/2013 for a data type error. thanks Bink for pointing out this. 

######################################################
# B = 1.164(Y - 16)                   + 2.018(U - 128)
# G = 1.164(Y - 16) - 0.813(V - 128) - 0.391(U - 128)
# R = 1.164(Y - 16) + 1.596(V - 128)
######################################################

image_out.save("out.bmp")
image_out.show()
By shrex999
3