There are many different formats that you can save your images in and like-wise sources to get images from or to create them.
As a rule mobile phone cameras will only produce a low resolution thumbnail which is generally too small to reproduce as a canvas print.
Digital cameras usually have a sliding setting which will allow you to take many images without downloading, but they will be fairly low resolution and so therefore won’t allow much enlargement without subsequent loss of quality. However if you set this to the opposite end, although you won’t be able to take as many images before downloading they will be of the highest resolution and therefore able to be enlarged and as a print on canvas.
Internet downloads are generally tiny images at low resolution intended for you to see what the images is before buying it and therefore are again too small for canvas printing. There are a few sites that will allow the downloading of larger format images for free. As a general rule of thumb, if the image is at least 5Mb when open and a fairly large image area they should be alright for most canvas print sizes.
If in doubt, you can always submit your images to our Image Check Team for verification of suitability and advice on best formats etc before placing your order for a canvas print or canvas photo.