I recently took a trip overseas and took over 1,000 photos with my iPhone 5 while I traveling. When I returned home, I wanted to share my photos with my family via Dropbox, but didn't want to upload the large iPhone photo image files into Dropbox and waste unnecessary space. Since iPhone photo files are usually over 2MB per photo, 1000 photos would have taken up over 2GB in space on my Dropbox account. Instead I wanted to quickly reduce the file sizes of all my photos so they were around 300KB per photo. Here's what I used to reduce multiple iPhone photo files all at once using Windows Live Photo Gallery
on Windows 7:
1) Sync your iPhone to your computer.
2) Open Windows Live Photo Gallery
(Download it here
3) Then in Windows Live Photo Gallery, click on "Import" and then in the pop-up box select your iPhone and click on the "Import" button.
4) Choose "Review, organize, and group items to import" and click Next.
5) Select the groups of photos you want to import and click Import.
6) Once your photos are imported you can hold down the "Ctrl" key and click on all the folders that your photos are now in. All the photos will now appear in the main window of Windows Live Photo Gallery.
7) Now within the Home tab, click on "Select all".
8) Click on the Edit tab, and then click on "Resize". In the Resize pop-up box, choose "Medium: 1024". Then click on Browse... to change the folder location so that all your newly saved photos will be separated from the larger photos. Then click on the "Resize and Save" button.
9) That's it! You now have just saved and reduced the file size of your iPhone photos, which are now much better for sharing with friends and family.
NOTE to Mac users: You can reduce the file size of your iPhone photos easily with iPhoto (which currently is not available to Windows Users). Here's how:
1) Import your photos into iPhoto.
2) Then do a batch export of all the photos you want to share.
3) Then export the photos from iPhoto at "medium" size…which will create smaller file sizes.