Comments on: Image Processing Tricks http://iPhoneIncubator.com/blog/windows-views/image-processing-tricks Tips and Tricks for iPhone, iPod, iPad and iOS Developers Sat, 28 Jan 2012 16:20:12 -0700 http://wordpress.org/?v=2.8.6 hourly 1 By: Mark http://iPhoneIncubator.com/blog/windows-views/image-processing-tricks/comment-page-1#comment-14908 Mark Tue, 01 Nov 2011 14:48:35 +0000 http://iPhoneIncubator.com/blog/?p=111#comment-14908 Great tips! Regarding the function - (UIImage *)addImage:(UIImage *)image1 toImage:(UIImage *)image2 It seems like this works perfectly on simulator and 320x480 screens, but if you jump to 640x960, image2's dimensions are calculated at 320x480 sizes (even if you have the @2x file ready). This is only happening for image2; image1 is calculated at the correct Retina size. Curious. Great tips! Regarding the function

- (UIImage *)addImage:(UIImage *)image1 toImage:(UIImage *)image2

It seems like this works perfectly on simulator and 320×480 screens, but if you jump to 640×960, image2’s dimensions are calculated at 320×480 sizes (even if you have the @2x file ready). This is only happening for image2; image1 is calculated at the correct Retina size. Curious.

]]> By: Nick http://iPhoneIncubator.com/blog/windows-views/image-processing-tricks/comment-page-1#comment-14965 Nick Fri, 22 Jul 2011 23:33:48 +0000 http://iPhoneIncubator.com/blog/?p=111#comment-14965 @Hakimo: The resulting image is returned from the addImage: method. You can use this in any way that you would normally use an UIImage object. @Hakimo: The resulting image is returned from the addImage: method. You can use this in any way that you would normally use an UIImage object.

]]> By: Hakimo http://iPhoneIncubator.com/blog/windows-views/image-processing-tricks/comment-page-1#comment-12699 Hakimo Thu, 21 Jul 2011 04:20:27 +0000 http://iPhoneIncubator.com/blog/?p=111#comment-12699 Hi, I'm not sure I understand how to combine the two images. I tried testing the code in my method file but how to I call the resulting image? Is there an xcode example for this? Thanks Hi, I’m not sure I understand how to combine the two images. I tried testing the code in my method file but how to I call the resulting image? Is there an xcode example for this?

Thanks

]]> By: Nick http://iPhoneIncubator.com/blog/windows-views/image-processing-tricks/comment-page-1#comment-14967 Nick Sat, 25 Jun 2011 23:46:35 +0000 http://iPhoneIncubator.com/blog/?p=111#comment-14967 @Sal: The method name "imageSavedToPhotosAlbum:" is arbitrary, but it must exist in your code because this method will be called when UIImageWriteToSavedPhotosAlbum completes. Other code examples may use the method name "image:". This is just as valid. I just happen to like very long, descriptive method names. The context parameter is only passed back to your method defined in the @selector. You can pass in the name of the image saved or some other information that might be useful in the called method. If you don't want any such information to be passed back to your code, then pass nil to the UIImageWriteToSavedPhotosAlbum function. @Sal: The method name “imageSavedToPhotosAlbum:” is arbitrary, but it must exist in your code because this method will be called when UIImageWriteToSavedPhotosAlbum completes. Other code examples may use the method name “image:”. This is just as valid. I just happen to like very long, descriptive method names.
The context parameter is only passed back to your method defined in the @selector. You can pass in the name of the image saved or some other information that might be useful in the called method. If you don’t want any such information to be passed back to your code, then pass nil to the UIImageWriteToSavedPhotosAlbum function.

]]> By: Sal Aguinaga http://iPhoneIncubator.com/blog/windows-views/image-processing-tricks/comment-page-1#comment-12117 Sal Aguinaga Sat, 25 Jun 2011 11:41:41 +0000 http://iPhoneIncubator.com/blog/?p=111#comment-12117 Regarding: `UIImageWriteToSavedPhotosAlbum(image, self, @selector(imageSavedToPhotosAlbum: didFinishSavingWithError: contextInfo:), context);` I've seen many examples showing: `UIImageWriteToSavedPhotosAlbum(imageCopy, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);` so I replaced `image` with `imageSavedToPhotosAlbum`, but it complained that `context`, which is at the end of your line, is an undeclared identifier. If I replace it with nil, the app crashes returning the following error: *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '+[NSInvocation invocationWithMethodSignature:]: method signature argument cannot be nil' I'm using ios 4.3.3 and Xcode 4.0.2. Any suggestions? Regarding: `UIImageWriteToSavedPhotosAlbum(image, self, @selector(imageSavedToPhotosAlbum: didFinishSavingWithError: contextInfo:), context);`
I’ve seen many examples showing: `UIImageWriteToSavedPhotosAlbum(imageCopy, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);`

so I replaced `image` with `imageSavedToPhotosAlbum`, but it complained that `context`, which is at the end of your line, is an undeclared identifier. If I replace it with nil, the app crashes returning the following error: *** Terminating app due to uncaught exception ‘NSInvalidArgumentException’, reason: ‘+[NSInvocation invocationWithMethodSignature:]: method signature argument cannot be nil’ I’m using ios 4.3.3 and Xcode 4.0.2. Any suggestions?

]]> By: Oded Ben Dov http://iPhoneIncubator.com/blog/windows-views/image-processing-tricks/comment-page-1#comment-7579 Oded Ben Dov Mon, 10 Jan 2011 21:56:25 +0000 http://iPhoneIncubator.com/blog/?p=111#comment-7579 There's a project that achieves fast image processing from the video camera, that is open source. It can help start anyone in the right direction - http://www.hatzlaha.co.il/150842/FAST-Corner-V2 Thanks! :) There’s a project that achieves fast image processing from the video camera, that is open source. It can help start anyone in the right direction –
http://www.hatzlaha.co.il/150842/FAST-Corner-V2

Thanks! :)

]]> By: Rikza Azriyan http://iPhoneIncubator.com/blog/windows-views/image-processing-tricks/comment-page-1#comment-7104 Rikza Azriyan Sat, 18 Dec 2010 10:51:02 +0000 http://iPhoneIncubator.com/blog/?p=111#comment-7104 Nica share.... Btw, i ever compile opencv on the iphone simulator. It was wonderfull, but lil bit confusing me to convert betwen UIImage to Iplimage and vice versa, and some of the rule of instant method parameter. So i tried to find another way to did it.. I have one question, can use CGImage Class to do image processing in realtime like opencv did? Thx b4 Nica share….
Btw, i ever compile opencv on the iphone simulator. It was wonderfull, but lil bit confusing me to convert betwen UIImage to Iplimage and vice versa, and some of the rule of instant method parameter. So i tried to find another way to did it..
I have one question, can use CGImage Class to do image processing in realtime like opencv did?
Thx b4

]]> By: Shiki http://iPhoneIncubator.com/blog/windows-views/image-processing-tricks/comment-page-1#comment-6422 Shiki Wed, 17 Nov 2010 12:25:53 +0000 http://iPhoneIncubator.com/blog/?p=111#comment-6422 Thanks for the info on handling UIImageWriteToSavedPhotosAlbum. Thanks for the info on handling UIImageWriteToSavedPhotosAlbum.

]]> By: Paul Michael http://iPhoneIncubator.com/blog/windows-views/image-processing-tricks/comment-page-1#comment-5717 Paul Michael Sat, 16 Oct 2010 09:29:03 +0000 http://iPhoneIncubator.com/blog/?p=111#comment-5717 Thanks for the merge image tip! Appreciate it. :) Thanks for the merge image tip! Appreciate it. :)

]]> By: Nick http://iPhoneIncubator.com/blog/windows-views/image-processing-tricks/comment-page-1#comment-14966 Nick Mon, 17 May 2010 23:37:54 +0000 http://iPhoneIncubator.com/blog/?p=111#comment-14966 @Art: A file with the extension .mm is typically used for C++. That may be why Xcode gets confused. @Art: A file with the extension .mm is typically used for C++. That may be why Xcode gets confused.

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