iPhone, iOS 5, iPad SDK Development Tutorial and Programming Tips

Example: Using Core Image Face Detection On A Live Video Feed

John — Thu, 17 May 2012 06:38:37 +0000

Some time ago I posted a tutorial on the basics of using Core Image face detection on the iOS platform.

Something that was asked in the comments thread for that post was how to use Core Image face detection on a live video feed – and whether it was fast enough.

Recently I received a submission from Jeroen Trappers showing how to use Core Image face detection on a live video feed, and place a moustache on the faces found within the video stream.

Here’s an image of the example in action from Jeroen’s site:

You can find the tutorial here.

The speed is respectable on newer iOS devices with a 640×480 capture resolution.

Added to the Core Image page.

Easy And Extremely Fast iOS UIImage Image Processing Library (Blur/Sharpen/Emboss)

John — Wed, 16 May 2012 20:02:57 +0000

With this Objective-C library for image filters based on Filterr.js and Core Image in iOS 5 there are a number of ways to easily process images. There are times however when you might need a bit more speed and don’t want to try rolling your own filter.

Today I came across an image processing library that is designed for speed and provides that enhanced speed by using Apple’s vDSP API. The library provides UIImage categories and provides allows you to easily apply sharpen, blur (box, gaussian and motion), and emboss filters.

The library is image-dsp from Mad Dog software and can be found on Github here.

You can read the original writeup about the category on the Mad Dog Software blog here.

You can read more about the vDSP Api On Apple’s site here.

A great library if you need some really fast image processing.

via @mugunthkumar, @flyosity

App Review Sites Listing Adds 50+ Sites – Traffic Rankings Updated

John — Wed, 16 May 2012 06:06:34 +0000

Not too long ago I shared news about a great template to help get reviewers to look at your app. About 3 years ago now I first added a listing of iPhone app review sites.

The iOS app review site list has once again been updated to 167 sites after many hours (and some help) and ranked by traffic.

A few people asked if there was a PDF available – I’m working on it, and should be out either later tonight or tomorrow.

You can find the listing here: app review sites.

Hope everyone enjoys the list – and sorry if I missed adding anyone’s app review site. You can post new sites in the listing below the comments.

Open Source iOS Library For Highly Customizable Animated Semi-Modal Views

John — Tue, 15 May 2012 06:25:40 +0000

In the past I’ve mentioned a great library that can be used to create elegant popup style modal panels.

Recently I received the submission of an interesting component that allows you to create partial modal views that cover the bottom of the screen and is styled after the National Geographic parks guide app.

The concept is similar to a UIAlertView however allows much more customization as you can insert any UIView elements within the model view and rather than just dim the screen the screen contents are shrunk, and shifted into the background with an accompanying animation.

Here’s a set of images from the Github page demonstrating how similar the components results are to the modal views in the National Geographic app:

The component is KNSemiModalViewController from Kent Nguyen.

You can find the component on Github here and read Kent’s writeup about the component on his site here.

You can find the National Geographic National Parks App on iTunes here.

The different animations and little touches with this component give it a very memorable effect.

Open source: Library For Easy Clear App Style (And More) Folding Transitions Between UIViews

John — Mon, 14 May 2012 19:36:12 +0000

Fold transitions were made famous by the popular Clear app, and previously I posted a gesture responsive UITableView with fold transitions.

Today I came across another library specifically for creating fold transitions. Using this library you can create a number of different fold transitions.

With this library you can create transitions between an UIViews, and UIViewControllers so you’re not just limited to a tableview. You can make both horizontal and vertical fold transitions. There’s also the ability to make it so any views pushed/popped by the UINavigationController can use one a fold transition. To top it off you get a number of different customization options for completely different folds.

Here’s an image from the Github page for the example illustrating some of the folds that can be created with the library.:

You can read the writeup on using this library on Mark Pospesel’s blog here and the library can be found on Github here.

Mark also has a more in-depth analysis on fold transitions that can be found here.

If you’re unfamiliar with the clear app you can find it on iTunes here.

An excellent library that makes it easy to come up with a fold transition that can suit your app.

Best Resources In iOS Development – May 14th, 2012

John — Mon, 14 May 2012 06:24:04 +0000

Another week gone by and once again here is the list featuring iPhone and iPad developer resources that have been most popular on this site in the past week.

This weeks list features a port of Twitter’s library for processing the text found within tweet’s, a vertical tab bar implementation perfect more adding simple navigation to ipad apps, and a source code example showing Cocos2D coded using Ruby (with RubyMotion).

Here are the resources:

Official Objective-C Version Of Twitter Text Processing Library Released - Twitter’s text processing library for dissecting the unique syntax found in tweets is now available in Objective-C.

Open Source iOS Control For Creating A Vertical Tab Bar - A control that behaves just like a tab bar (although with unlimited room for items), but displays vertically.

Example: iOS Cocos2D With Ruby (RubyMotion) - A demo implementation of Cocos2D running with RubyMotion.

Tutorial: In-Depth Guide To Handling And Transferring Files With iCloud From Within Your Apps - A step-by-step tutorial showing how to handle files within an app and use those files with iCloud.

Open Source: Custom UITableViewCell Implementation For Easy Swipeable TableView Cells - A UITableViewCell replacement that you can use to add swipeable cells to any UITableView.

Extremely Handy iOS UI Event Tracking Library (Perfect For The Performance Obsessed) - Very nice library for those times when you need to know when the user is interacting with the interface.

Online Console Allowing You To Test Out RubyMotion (Ruby For Native iOS App Development) - A console you can use to demo the syntax of the new Ruby on the iOS SDK implementation RubyMotion.

Open Source Library Providing An Objective-C Version Of .NET’s Reactive Extensions - A library from Github that allows you to use the reactive programming paradigm on the iOS platform styled after reactive extensions.

Thanks for reading, please bookmark and share this post!

Example: iOS Cocos2D With Ruby (RubyMotion)

John — Sat, 12 May 2012 22:25:29 +0000

A couple of days ago I mentioned an interactive console demonstrating RubyMotion that you could use to check out how programming with Ruby is using the iOS SDK.

Today I came across a RubyMotion project “CocosMotion” in which Sean Scally has Cocos2D iPhone up and running with RubyMotion.

There’s a few issues, but it looks like they are being actively worked on right now. While I wasn’t too interested in RubyMotion at first I’m looking forward to seeing some examples coded with Ruby.

You can find the project CocosMotion on Github here.

You can read and contribute to the original post in the Cocos2 forum here.

Added to the Cocos2D Example page.

Open Source iOS Control For Creating A Vertical Tab Bar

John — Fri, 11 May 2012 23:21:27 +0000

In the past I’ve mentioned a number of excellent navigation components for iPad apps such as stacked view creator PSStackedView the and grid style navigation controller LIExposeController.

I’ve come across another controller that is a bit simpler allowing you to easily create a navigation control in the form of a vertical tab bar.

This tab bar is that it behaves just like a UITabBar – just vertical. It can also have an unlimited number of items, if you have more items than fit on the screen it will scroll just like a UITableView (because it is one).

Here’s a screenshot from the Github page showing the control in action:

This iOS control is FSVerticalTabBarController from Future Simple and can be found on Github here.

A nice clean easy to implement navigation control.

Tutorial: In-Depth Guide To Handling And Transferring Files With iCloud From Within Your Apps

John — Fri, 11 May 2012 07:58:18 +0000

iCloud is a topic that I’ve brought up several times, and the most popular resources have been an excellent library that provides a blocks based syntax for upload images and documents to iCloud, and an in-depth guide on using iCloud and Core Data together.

I’ve also mentioned some excellent beginner iCloud tutorials, and today came across a tutorial that is somewhat more advanced.

In this tutorial by Ray Wenderlich you’ll learn some more advanced iCloud topics by building an app from scratch that covers iCloud usage in depth. This is an excellent tutorial if you want to understand how to handle files within your apps and use them with iCloud.

Here’s a summary of what you’ll learn taken from the tutorial page:

Create, Read, Update, and Delete documents – both on iCloud *and* locally

Create documents consisting of multiple files with NSFileWrapper

Give previews of documents in the master view in an efficient manner

Allow a toggle for the user to enable/disable iCloud in Settings

Move/copy files to and from iCloud when user switches

Alllow renaming and deleting files – the safe way

Deal with conflicts and document updates

You’ll find the tutorial in 4 parts: Part 1, Part 2, Part 3, and Part 4.

Added to the iOS 5 tutorial page.

Online Console Allowing You To Test Out RubyMotion (Ruby For Native iOS App Development)

John — Thu, 10 May 2012 22:15:08 +0000

You may have seen RubyMotion being lauded by mainstream tech sites – a toolchain that allows you to develop and test native applications for the iOS platform using Ruby.

Unless you were lucky enough to try out RubyMotion in beta you might be wondering if you RubyMotion is your thing..

The guys at Pieceable have put together an interactive in-browser demo console using their app viewer so you can play around and see if RubyMotion is your thing.

You can find the interactive demo here along with a number of tips of things you can try out.

You can check out more about Rubymotion on their site.

If you’ve been wanting to see if RubyMotion is your thing be sure to take a look – it helped me decide that Objective-C is now more my thing.