When you resize a photo in Picasa, you're creating a new copy with an adjusted image resolution (pixel count) and with all photo edits applied. The original photo on your hard drive is never altered.
You can reduce picture size in Picasa by exporting, emailing, or uploading your photos to Picasa Web Albums.
Resize by exporting
Exporting lets you change photo size while controlling the JPEG compression (image quality) introduced by your applied photo edits. The result is newly resized copies of your photos, saved to your hard drive. During the export process, you can adjust both the "Image Size Options" and the "Image Quality" settings in the "Export to Folder" screen.
- When selecting image size, choose the "Resize to" option and adjust the size slider. The number of pixels you select with this slider determines the length or height of your photo (whichever is longer). The other dimension is determined automatically to maintain the aspect ratio of the photo.
- Select the image quality for your photo using the "Image Quality" drop-down menu:
- Automatic: Preserves the original image quality
- Normal: Balances quality and size
- Maximum: Preserves fine detail for large file sizes
- Minimum: Yields some quality loss for small file sizes
- Custom: Lets you to select your own value
Resize by emailing
If you're sending pictures by email, you may want to reduce the picture size in order to get under the attachment size limitation. To change the size of the pictures you email from Picasa, follow these steps:
- In Picasa, click Tools > Options (Windows) or Picasa > Preferences (Mac).
- Select the Email tab.
- Use the slider to set your desired pixel size when emailing multiple photos. Use the radio buttons to set the pixel size for emailing single photos.
- Click OK.
Resize by uploading to Picasa Web Albums
If you're sharing a large number of photos, you may not want to upload all of the photos at their original size. When you upload images from Picasa, you can choose the upload size using the "Size to upload" drop-down menu or else you can set your preferred default size for photo uploads.