26 February 2013

How images are handled in Google Blogger

What is described bellow is only useful to know in case you upload big images (more than 1600 pixels) to Blogger. Google will automatically re-size these big images to 1600 pixels (in Blogger) and 2048 pixels (in Picasa / Goggle+) to be better suited for the Web and then be displayed properly on a computer screen. Small and medium size images (less than 1600 pixels) will be left untouched in Blogger / Picasa / Google+ (see example n° 2 bellow).

Rules:

- If an image is added to Blogger, it will be stored in a Picasa / Google+ album which has the same name as the Blog.

- The image put in Picasa will:
  • be resized (scaled down) to 2048 px max (width or height);
  • have the printing resolution set to 96 ppi max.
- The image in Blogger (taken from Picasa) will be displayed:
  • in small (200 px) or medium (320 px) or large (400 px) or x-large (640 px) or original size (1600 px max);
  • if you click on it: in original size (1600 px max);
  • the printing resolution will be 96 ppi max (as it is the image from Picasa).
- The image URLs will look something like this:

Picasa:

https://picasaweb.google.com/lh/photo/alSavum6Z63rVI6hLSs0KJhLRzmKGmo_MZljepmK1tE?feat=directlink → 2048 px max

Blogger:

http://4.bp.blogspot.com/-Wh09JwWlMjU/USzLLKKgGlI/AAAAAAAABc0/AvCflXWOQKg/s1600/test.jpg → 1600 px max

- s1600 = image displayed at 1600 px max.
- If you replace s1600 by another value (e.g. s1200), the picture will be displayed at 1200 px max.
- If you replace s1600 by a value bigger than 2048 (e.g. s4000), then the image will be displayed at 2048 px max (max size in Picasa).
- If you set sXXXX, and the size of the image is YYYY px, with YYYY < XXXX, the image will be displayed at YYYY px.

E.g.

1) image1.jpg: 4000 px X 2000 px @ 600 ppi (very big image with very high printing resolution)

In Picasa:

- 2048 px X 1024 px @ 96 ppi

In Blogger:

- 1600 px X 800 px @ 96 ppi (default = s1600)
- 2048 px X 1024 px @ 96 ppi (s2048, s3000, etc.)
- 1200 px X 600 px @ 96 ppi (s1200)

2) image2.jpg: 600 px X 300 px @ 72 ppi (small image with small printing resolution)

In Picasa:

- 600 px X 300 px @ 72 ppi

In Blogger:

- 600 px X 300 px @ 72 ppi (default = s1600)
- 600 px X 300 px @ 72 ppi (s2048, s3000, etc.)
- 300 px X 150 px @ 72 ppi (s300)

Remarks:

- If the image has been re-sized by Picasa, the Program name metadata of the image file will be set to Picasa.
- If you edit the image in the Picasa web interface, the Program name metadata of the image file will be set to picnik.com.