I was doing some backups of my digital photos and I noticed that some of the photos were imported from my camera twice to two different folders. That's not the issue.
The issue is I was comparing file sizes and notices some of the duplicates were smaller (4.6MB vs 5MB). I noticed the smaller ones have
Microsoft Photo Viewer in the Program Name field of the Exif data, whereas the larger ones have my camera model in that field. Also, the height and width dimensions have been swapped (the image was rotated).
Why are my photos getting manipulated?
Does the difference in file size indicate that I'm losing some image quality in the manipulation ?
- or is it possible that Windows uses a more efficient JPEG compression algorithm than my camera ? (Assuming they are both using the minimum level of JPEG compression)
- or is there something about the orientation of the photo that would make the JPEG compress differently ?