On 1/26/2017 9:11 PM, Paul B. Gallagher wrote: > David E. Ross wrote: > >> I tried to recreate your problem. However, a very sharp JPEG file >> that is 1852x1852 px is only 750 KB on my PC. > > Image file size depends both on the number of pixels and on the color > depth. 1852×1852×2/8=857,476 bytes = 837.38 kB (black and white) is much > less than 1852×1852×1,048,576/8=449,564,377,088 bytes = 439,027,712 kB = > 428,738 MB (true color). > > I haven't bothered to account for check bits and the efficiency achieved > by the lossy JPEG format, but the principle holds: color depth affects > file size. > I took a color photograph 2615 x 1656 px with 24-bit true color and a resolution of 350 px/in. The file size was 1.18 MB (European 1,18 MB).
I went and repeated my analysis but with different steps. This time, I resized it to 1852 x 1852 px, which distorted it. The resulting file was 2.12 MB (European 2,12 MB). I then reduced it to 500 x 500 px, which still looked quite sharp. That resulted in a 90 KB file. Previously, I cropped the photo to get a square 1656 x 1656 px image and then resized it to 1852 x 1852 px. Obviously, cropping caused a loss of pixels and thus a reduced file size. Ooops! -- David E. Ross <http://www.rossde.com/> When the President of the United States makes a statement of national importance, I want to see his face as he is talking. At the least, I want to hear his voice. Donald: Stop tweeting. Otherwise, how do we know the message really comes from you? _______________________________________________ support-seamonkey mailing list [email protected] https://lists.mozilla.org/listinfo/support-seamonkey
