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I want to create an iOS app that utilizes full-screen photographs, which may turn into a lot of wait time for the end user if they are on a slow connection. Instead of showing them a "loading" icon, I want to display the image as it loads either linearly (from top to bottom the way a web browser might load images) or more interestingly, in a non-linear fashion. By that I mean, is there a function/method that would load pixels/sections randomly from any part of the image until the image is fully complete?

user3314426
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1 Answers1

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You should look at 

CGImageSourceCreateIncremental and CGImageSourceUpdateData

methods here https://developer.apple.com/library/ios/documentation/graphicsimaging/Reference/CGImageSource/Reference/reference.html

You can also try NYXImagesKit library (https://github.com/Nyx0uf/NYXImagesKit)

Algorithm description - http://cocoaintheshell.com/2011/05/progressive-images-download-imageio/

Sample:

NYXProgressiveImageView * imgv = [[NYXProgressiveImageView alloc] init];
imgv.frame = CGRectMake(0, 0, 320, 480);
[imgv loadImageAtURL:[NSURL URLWithString:@"http://yourimage"]];
[self.view addSubview:imgv];
Avt
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  • Thanks! Looks like this is the progressive version. Do you know of any function that would instead load random pixels/areas until the image is fully loaded? – user3314426 Feb 15 '14 at 22:55
  • No. It should be rather difficult - I do not think there is a Cocoa class that supports random (non-progressive) image displaying. Anyway you can try to find a third-party library for that. – Avt Feb 15 '14 at 23:03
  • Also you can use images with interlace - probably it will a little improve loading/displaying process. – Avt Feb 15 '14 at 23:05