Most commonly known and popular FREE image hosts will generally always down scale and compress uploaded images if they're large sized. Resulting in lost detail.
When I wish to share lossless images that haven't been down sized or scaled I use this website.
http://3ezy.net/
A quote from their description.
Lossless Image processing
Many free or even paid hosting providers will find the best way to save cost by reducing quality of images uploaded. Pictures are also resized and sometimes watermarked (website logos added). All of which further reduce the quality. Although not apparent, the quality deteriorates overtime as people download and upload the same content over the web. For high quality images the loss of quality is a lot more apparent.
At 3ezy.net we do two things. 1. Always use LOSSLESS compression. Which basically means we don't reduce quality at all, just discard useless extra information stored within images. This helps in faster loading of pictures in web browsers and does not affect the quality of images at all. We then resize the uploaded pictures. However the original (Lossless) image is still stored and is viewable directly. Due to the size of the lossless image it is not recommended to hotlink them in websites/forums directly specially if they are larger than 800px in width as it makes difficult for people to see the content properly alongside the huge pictures. We provide you with the necessary tools so you can show a preview (thumbnails with forum and html code) to other people and they can choose to click and see the large picture in a fresh new window ...unobstructed. We support lossless compression of JPEG, GIF and PNG formats as of now.
Just a notice that it might take up to 5 - 10 minutes for the image link to be sent to your email. It isn't like Imgur or Tinypic where you're giving a direct URL instantly. Sometimes I get the email instantly.
The good thing about 3ezy aswell is it allows direct hotlinking.
If you don't need direct hotlinking you might as well share the lossless images in non-compressed .zip or .rar and send it to friends or family through your selected file sharing service [Dropbox, Mediafire, Mega etc] or a USB the next time you see your family or friends give it to them.
Sites such as Minus, Imgur and Imageshack might also let you share your lossless images without down scaling or compressing but most sites have pricing for that privilege.
Cheers.
