.tec files are generally thumbnail images of either 104X74 or 240X320 size 1 tec file can contain hundreds of these images, I transferred the tec files from my phone to pc then made an iso/img file of the folder and used Dejpeg to convert the files and rcovered 24,000 images from around 4,500 .tec files

copy the .tec files to your computer make an iso or img file of them then use Dejpeg to convert them to jpeg files worked fine for me using free version recovered 24,000 images from 4,570 .tec files