An Important Update

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If you did not use a Blogger / Google account when you Followed this blog, years ago, you are probably not Following now . During the past...

Friday, July 24, 2015

Photo Quality Is Sometimes Degraded By Hosting

We see occasional signs of concern, in Blogger Help Forum: Get Help with an Issue, about photo quality in Blogger.
I take high quality pictures with my camera - and when I edit them, using various platforms, they still have the same quality. But the second I upload them to my Blogger post, the quality gets really bad.
This is a very civilised comment, not all are so objective.

Photo quality has been a concern, for years. There are so many ways photos can be degraded, once they hit the Internet.

Photo quality can be compromised, in various ways - and we see differences between a typical photo, as it comes out of the camera, and how it is displayed, as part of a Blogger blog.
  • Aspect ratio.
  • Compression / encoding technique.
  • Hosting service.
  • Resolution.
  • Sizing.

Aspect ratio.

Any time a photo is resized, the aspect ratio may change. Any change in aspect ratio can affect photo quality. Some changes will be more noticeable than others.

An image that is originally taken with a 3 x 5 aspect ratio will look different, if resized to 4 x 7. A 3 x 5 aspect could be possibly resized (and re compressed) to a 6 x 5 - or a 3 x 10 - since "3 x 5", "6 x 5", and "3 x 10" are integral multiples of each other. A 4 x 7, on the other hand, will produce resizing artifacts, more obvious than the other three.

Compression / encoding technique.

".bmp", ".jpg", "png" are all going to store photos differently. A photo created as a ".bmp" will look different if displayed as a ".png".

Converting from one format to another will produce conversion artifacts.

Hosting service.

Different hosting services will add their own photo degradation factors, and differing aspect ratios, compression / encoding, and resolutions. Not everybody will use Blogger post editor, and Google / Picasa hosting.

Flickr, Instagram, PhotoBucket, and many others will all have their own oddities - and produce image degradation.

The Google+ "Auto Enhance" feature was not welcomed by all serious photographers, who use Blogger and / or Google+. Other hosting services may have their own "tweaks".

Blogger / Picasa has their own oddities. Blogger uses a special photo library, which resizes a given photo when displayed - to serve multiple thumbnail sizes, plus the "full" size, of each photo.

Little icons / watermarks, added by the various hosting services, will compromise photo quality. PhotoBucket, Pinterest, and others may add little icons.

Resolution.

Some images, with reduced resolution, won't ever look the same. A 16MP resolution in the camera, just will not look as crisp in Blogger, using 4MP. Some compromise, to reflect the reality of limited bandwidth suffered by your readers, is always going to be necessary.

Photos displayed on the Internet won't be identical to photos hosted by you, on your local camera / computer combination, in your home or office.

Sizing.

Blogger has a special photo library, which gives us multiple dynamic thumbnail sizes - plus the full size, linked from the thumbnail displayed in the post.
  1. Small (200 x 200).
  2. Medium (320 x 320).
  3. Large (400 x 400).
  4. X-Large (640 x 640).
  5. Full size (1600 x 1600).

A photo that starts out in a size that is not a precise mathematical multiple of any of the 4 sizes, when resized and added to the Blogger / Picasa photo libraries, is going to show artifacts. The artifacts will be seen as "poor quality".


Small - 200 x 200 px.



Medium - 320 x 320 px.

We see Large - 400 x 400 px, X-Large - 640 x 640 px, and XX-Large - 1024 x 1024 px, below.














If resizing involves a larger size than initially provided, you'll see blurring and pixellation. If a smaller size, then random irregularities - some you may not realise - but they will be present. The less integral the change in "aspect ratio", the more degraded quality of the photo.

The full picture.

If you publish your photos (images, pictures) on Blogger (Google Photos, Picasa), and various non Google services, be prepared for some compromise in "quality". The more times you copy, upload, download, etc, the more chances for "degraded quality".

Dude, hit me with a comment!