demo.lua

require 'cv.highgui'
require 'cv.videoio'
require 'cv.imgproc'
require 'nn'
--require 'clnn'

local cap = cv.VideoCapture{device=0}
if not cap:isOpened() then
  print("Failed to open the default camera")
  os.exit(-1)
end

cv.namedWindow{winname="edges", flags=cv.WINDOW_AUTOSIZE}
local _, frame = cap:read{}

local net = torch.load'nin.t7':float()
local img_mean = torch.load'ilsvrc_2012_mean.t7'.img_mean:float()
local synset_words = torch.load('synset.t7','ascii')

local M = 227

while true do
        local w = frame:size(2)
        local h = frame:size(1)

        local crop = cv.getRectSubPix{src=frame, patchSize={h,h}, center={w/2, h/2}}
        local im = cv.resize{src=crop, dsize={256,256}}
        local im2 = im:float() - img_mean
        local I = cv.resize{src=im2, dsize={M,M}}:permute(3,1,2):clone()

        local _,classes = net:forward(I):view(-1):float():sort(true)

        for i=1,5 do
          cv.putText{
            img=crop,
            text = synset_words[classes[i]],
            org={10,10 + i * 25},
            fontFace=cv.FONT_HERSHEY_DUPLEX,
            fontScale=1,
            color={255, 255, 0},
            thickness=1
          }
        end

	cv.imshow{winname="edges", image=crop}
	if cv.waitKey(30) >= 0 then break end

	cap:read{image=frame}
end

Doesn't OpenCV open by default the images as BGR?

@fmassa NIN expects images in BGR and we give it BGR, right?

Indeed !