what is the problem with this png image

[sturkmen72]

i am using OpenCV and tried to use latest version of libpng in OpenCV. i can't open the image above when i use newer versions of libpng than 1.6.25

error message libpng error: IDAT: invalid distance too far back
my OS is windows 10 64bit

[glennrp]

As you reported, and according to "pngcheck -v" it contains the "too far back" error in the IDAT (zlib) data. You can use pngfix to repair it. pngfix comes with the libpng16 distribution, and you run

pngfix --out=problem-fixed.png problem.png

to repair it. Do you happen to know how the image was created?

Glenn

[sturkmen72]

thank you for the explanation

it is one of INRIA Person Dataset images ( most of them has same problem)

i can open it with libpng 1.6.25

[liquidmetal]

Could you attach a link to the original png file? The embedded image might have gone through Github's image compression.

[sturkmen72]

@liquidmetal thank you for your care. you can use the image above. https://user-images.githubusercontent.com/12151541/32344092-b1eefb8a-c016-11e7-9ab4-3e08fa0564c5.png