Error HTTP on image upload with Nginx

Hello, wordpress community ! Sorry for my english.

I have an image upload problem. I can’t solve.

The problem comes with a large size images.

I tried all the solutions set out on the forums.

For example :

Chmod is good
Memory for PHP : OK
WP_MEMORY_LIMIT : OK
Imagick by replacing php-GD
client_max_body_size : 200M
Deactivate Plugins …

Now I have no more idea.

The problem may be with nginx, is it possible?