Legacy ImageMagick Discussions Archive

Hi,

I use IM for verifying my application behavior(testing purpose) using the 'compare' function. But if the image has some brightness issue specific to rendering h/w, my tests are failing.

Image1 :
Image2 :

Normally for comparison purposes, I used NCC metric in gray scale mode. I tried NCC, AE and AE with fuzz on the mentioned images, but none of them showing a positive result. (at least 80% accuracy required)

Image size : 82x20



I want to pass the comparison, if their is a yellow highlight and the text in the region is exactly what I've specified.
Can some one help me to resolve this issue ?

The two yellow colors are too different to pass with a small error. You must set your error tolerance higher for acceptance. The only way I can see that you will get a low metric result is using -metric AE and raising the -fuzz value rather large

compare -metric AE -fuzz 85% 2uetv90.png e05rib.jpg.png null:
0

You also have a scaling problem: the text is a slightly different size. You might pre-process each image to crop away the background, then rescale one to the same size as the other.

Thanks Fred, Snibgo for your suggestions. I'll try increasing the fuzz percentage as well as do the scaling properly

Apart from the scaling, you could convert all colors but black to white and then do the comparison.

convert image -fuzz XX% -fill white +opaque black newimage

Thanks Fred for the inputs. But it won't suffice my specific requirement, as I need to verify whether the yellow highlight is present in the region along with the text.

So you do two tests: one for the text, the other for the colour.

Two tests, I think will be expensive in terms of time. Any way, I'll have a try.

Can any one give inputs on how to find scaling factor of similar images, but scaled differently. Is there any standard methodology for identifying scaling measures b/w two images. If we found the scaling factor, how we can rescale it, using IM ?

Thanks in Advance.

see -resize
http://www.imagemagick.org/script/comma ... php#resize
http://www.imagemagick.org/script/comma ... p#geometry