Basic question about saving a jpg as a tif file

I brought a file into my computer from my camera. It is a .jpg file -
1,868kb with dimensions 2592 x 1944. I save it as a .tif file and that
file is 14,766kb with the same dimensions. My question is this - where
did the extra 12898kb come from? The original file from the camera I
assume brought in just so much information (1,868kb). Is the remaining
balance something generated by my computer? What is it? I know raw puts
everything the sensor gathered, but .jpg is an edited and lossy
compression. I am confused. Thanks in advance for making this
understandable.

Frank

On 29 Gen, 20:07, Frank Calidonna wrote:
I brought a file into my computer from my camera. It is a .jpg file -
1,868kb with dimensions 2592 x 1944. I save it as a .tif file and that
file is 14,766kb with the same dimensions.

jpeg is a compressed (with loss) format, TIFF is an uncompressed
format
so TIFF use 8 x 3 bit per pixel (if 8 bit per color are used)
Do 2592 x 1944 x 3 / 1024 and will obtain 14,7 MByte

PC doesn't add any information (how could?) but just interpolate the
info coming from jpeg.
The advantage with TIFF is not to lose anything saving and re-saving
the image, instead of jpeg that degrease quality at any chenge and
save.
But, if original picture is degraded, also the TIFF one will be, just
not degrading more.