How to compare 2 images and generate the report?

divkrishna

Hi,

I wanted to compare two images through Sahi. Can you pls help me out.

Thanks,
Krishna

globalworming

Hi divkrishna

my suggestion would be to download the images through sahi and then _execute a script to compare these images. I can recommend http://www.imagemagick.org/Usage/compare/
Then _readFile the result and _assert if there is a difference.

Regards
Wormi

divkrishna

Thanks,

I have another question that once i compare images then it will be in form of image(compare.jpg) , so how will i use _readfile to read the image?

Awaiting for your reply.

Thanks,
Krishna

globalworming

Your compare.jpeg colors red all differences in the 2 compared images. So you need o check for the amount (or existance) of red in the images.
Check for red:
Write the output from from imagemagick into a file

identify -verbose compare.jpg

_readFile the file and check the channal statistics if reds mean is like above 50%

and/or

Write the result from

compare -channel red -metric PSNR assertImage.png existsImage.png  compare.png 

into a file. If

_readFile() == "inf"

then there is no difference in the picures.

@see all from http://www.imagemagick.org/script/compare.php
Add imagemagick to Sahi: http://im4java.sourceforge.net/api/

Or maybe you could just let an _execute() fail. Like when execution of compare not returns "inf" fail with exit status and wrap this _execute in a try-catch-block.

Nana111

HI there
I have never tried to compare two images through Sahi.I want to know that if there is any image tool which supports to do that directly.I have tried another image tool:
http://www.rasteredge.com/how-to/csharp-imaging/
But it said that they can not work with Sahi.Thanks for any suggestions.

globalworming

There is no "direct through Sahi" as far as I know. But as I said you can include Imagemagick in Sahi to provide image comparison via Sahi Api.

Nana111

Thanks for your nice sharing.I'll have a try