Here is a How-to guide to DIY Chinese Visa Photo.
The requirement of it is 33mm x 48mm, a little bit smaller than 2 inches.
Here is a sample picture from official China embass website.
So just take a picture by yourself and use any photo editing tool you like.
1) Make it 300dpi.
2) Crop the pic per above
3) Change the image size to 470 pixel width, 600 pixel height.
4) Prepare all pictures of your family.
5) Create a new blank image file with 1800 pixcel width, 1200 pixel height, 300 dpi.
6) Copy and paste the pictures prepared in step 4 here.
So the fiale is looks like below
You can put up to six photos on it. Then save it in the highest quality JPEG format file.
Send it to any online photo printing service site and order it to 4X6 inches glossy finish.