Develop

add a new openEXR check lib for blank channel
the Imath and OpenEXR lib in script can be download from here:
http://www.excamera.com/sphinx/articles-openexr.html
package link is  
http://excamera.com/files/OpenEXR-1.2.0.tar.gz
the doc link is 
http://excamera.com/articles/26/doc/openexr.html



here is the example:

import OpenExrReader as oer
aa = oer.ExrCheck()
aa.setExr(r"bg_bad.exr")    // set image path
aa.getChannel()       //get channel name ,return a list like ['R','G','B','A']
aa.isChannelBlank('R')    // return true if this channle is blank,False if this channle has data in it

//this is for a exr
def checkExr(fileName):
    isPicEmpty = 1
    image = OpenExrReader.ExrCheck().setExr(fileName)
    for channel in ['R','G','B']:
        if not image.isChannelBlank(channel):
            isPicEmpty = 0
            break
    return isPicEmpty