modify float precision in img_conv2
modify float precision in img_conv2

lcy-seso/Paddle,reyoung/Paddle,lcy-seso/Paddle,putcn/Paddle,reyoung/Paddle,pengli09/Paddle,luotao1/Paddle,lcy-seso/Paddle,Canpio/Paddle,pkuyym/Paddle,jacquesqiao/Paddle,lispc/Paddle,lispc/Paddle,PaddlePaddle/Paddle,pkuyym/Paddle,pkuyym/Paddle,putcn/Paddle,Canpio/Paddle,reyoung/Paddle,tensor-tang/Paddle,putcn/Paddle,pkuyym/Paddle,hedaoyuan/Paddle,PaddlePaddle/Paddle,pengli09/Paddle,PaddlePaddle/Paddle,baidu/Paddle,lispc/Paddle,hedaoyuan/Paddle,luotao1/Paddle,yu239/Paddle,lispc/Paddle,lispc/Paddle,reyoung/Paddle,reyoung/Paddle,chengduoZH/Paddle,hedaoyuan/Paddle,yu239/Paddle,chengduoZH/Paddle,hedaoyuan/Paddle,PaddlePaddle/Paddle,jacquesqiao/Paddle,Canpio/Paddle,PaddlePaddle/Paddle,tensor-tang/Paddle,baidu/Paddle,Canpio/Paddle,pengli09/Paddle,lispc/Paddle,QiJune/Paddle,tensor-tang/Paddle,QiJune/Paddle,tensor-tang/Paddle,tensor-tang/Paddle,yu239/Paddle,pengli09/Paddle,hedaoyuan/Paddle,Canpio/Paddle,baidu/Paddle,putcn/Paddle,luotao1/Paddle,Canpio/Paddle,reyoung/Paddle,yu239/Paddle,lispc/Paddle,pengli09/Paddle,hedaoyuan/Paddle,jacquesqiao/Paddle,chengduoZH/Paddle,lcy-seso/Paddle,lcy-seso/Paddle,luotao1/Paddle,yu239/Paddle,QiJune/Paddle,hedaoyuan/Paddle,luotao1/Paddle,baidu/Paddle,putcn/Paddle,pkuyym/Paddle,jacquesqiao/Paddle,QiJune/Paddle,pengli09/Paddle,luotao1/Paddle,QiJune/Paddle,jacquesqiao/Paddle,putcn/Paddle,PaddlePaddle/Paddle,lcy-seso/Paddle,yu239/Paddle,hedaoyuan/Paddle,Canpio/Paddle,PaddlePaddle/Paddle,jacquesqiao/Paddle,yu239/Paddle,chengduoZH/Paddle,baidu/Paddle,yu239/Paddle,pkuyym/Paddle,pengli09/Paddle,lispc/Paddle,QiJune/Paddle,luotao1/Paddle,pengli09/Paddle,Canpio/Paddle,chengduoZH/Paddle