iOS Sending And Receiving High Resolution Images

[loon3y]

in my app

we're pushing high resolution images and receiving high resolution images from the web service


do apps like face book and instagram compress these images and uncompress them?


or do they actually send the full sized image back and forth?

 

[Snowshiro]

There's not usually a lot of mileage in compressing most common image formats, as they already undergo compression as part of the encoding process.

You might get a modest benefit of a few percent, but any more than that would likely mean quality loss.

 

[Duncan C]

There's not usually a lot of mileage in compressing most common image formats, as they already undergo compression as part of the encoding process.

You might get a modest benefit of a few percent, but any more than that would likely mean quality loss.

It depends on the file format.

JPEG doesn't get any smaller with additional compression, and will sometimes actually get bigger. I don't think BMP images are compressed at all. TIFF images may or may not be compressed, depending on the settings. The same goes for PNG files. Not sure about GIF, save for simple run-length encoding.

 

[Snowshiro]

By common image formats, I meant the big three: JPEG, PNG and GIF. BMP and TIFF aren't all that commonly used in internet-based applications.