I have around 100 PNGs (that I created) that I want to create an animation out of. I however created the animation in a vector graphics editor, therefore each PNG has a white background. How do I make Xcode not show the white background and instead just the image itself? I will be displaying the animation in a transparent window, so a background completely ruins the effect.
Note I'm using Xcode 3.2.6 on Snow Leopard. I'm specifically asking about a Mac application not an iOS one.
I recommend exporting your images again with a transparent background. That would save you a lot of trouble. If that's not an option, have a look at Quartz 2D Masks.
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I'm developing a iOS app that is using custom UIButtons with round shape. I wanted to add Image to these buttons and would like to know if I use IB to select an image from my project, do I have to also worry about 2x retina images for retina display?. What should be the image size for both non-retina and retina devices (all iPhones (including iphone 5) and iPad including mini) when I embedded them from IB?
Is there a best resource available on the Internet to get these pngs files for buttons?
Yes you should use all the images. you should just add the images with proper names to the resources folder. And just select the non-retina image rest the compiler will take care of.
http://www.idev101.com/code/User_Interface/sizes.html
The above link will help you with the images sizes
It is easy. Goto interface builder and on the right hand panel you will see this -
All you need to do is first configure your button as custom then include a image file in your project through xcode and then you can select that image in the dropdown in background or image property.
Note that all this is possible to do through code also, its just that IB makes it interactive. Hope this helps.
I am about to launch a new app and would lik eto increase quality of the graphics. In my case the graphics is the logo and the custom buttons. I do not know if this impact Core Plot but that is also part of the package.
There is quite a few posts about this but there are still things i do not fully understand.
I am reading this quote from "amattn":
It's trivial:
1.Only include #2x images in your project.
2.Make sure those images have the #2x suffix.
The system will automatically downscale for non-retina devices.
The only exception is if you are doing manual, low level Core Graphics drawing.
You need to adjust the scale if so. 99.9% though, you don't have to worry about this.
From this post: Automatic resizing for 'non-retina' image versions
My question in regards to this is:
1. Should i do the testing on retina simulator only, as if i place a #2 grapic on
non-retina it will be too big? ...or is there an other way of doing it?
2. Should i always use a ImageView or is it OK to drag the image on the screen,
this is the logo i am talking about?
3. What about custom made buttons with images, how should i do with those?
4. What is the normal process to manage the different screen sizes, do people
add images for all displays or using this type of process?
Should i do the testing on retina simulator only, as if i place a #2 grapic on non-retina it will be too big? ...or is there an other
way of doing it?
It doesn't really matter which simulator you test on because as long as your non-retina and retina graphics are named correctly (image and image#2x) the correct image will be displayed automatically.
Should i always use a ImageView or is it OK to drag the image on the screen, this is the logo i am talking about?
When you drag and image from the project directly onto a view in interface builder you don't really see it happen but it has automatically created and image view which is containing the image your dropped in.
What about custom made buttons with images, how should i do with those?
[myButton setImage:[UIImage imageNamed:#"myFileName"]];
As shown in the above code you should always use the non-retina fle name when you reference the image a UI element should use. That was if iOS detects the device is retina it can automatically use the #2x version in its place.
What is the normal process to manage the different screen sizes, do people add images for all displays or using this type of process?
Yes, including multiple image resolutions common practice and is required for iPhone apps (not sure about iPad) to include both retina and non-retina images. But regardless of the requirements, you should definitely support both device resolutions to keep your customers happy!
The white background in my apple touch icon turns black?? My white background isn't transparent. The icon has a white triangle, red circle and black text. The only thing I can make out is the white triangle and red circle. Any idea whats causing this and how to make the icon keep its white background?
Much appreciated.
I'm not sure exactly what it was, but I may have narrowed it down.
The first time I uploaded the images they may have had the transparent background.
The second time I uploaded them I added the white background, but the png save for devices setting still had transparency checked.
The third time I uploaded them I saved them without the transparency checked but still got the black background.
All along I think the iOS Safari browser had the first set of images stored in cache. After clearing the cache the new image showed up with no problem.
Edit: Its the transparent background that turns it black.
As gstricklind found, if your png has alpha channel transparency, iOS will unfortunately ignore any "precomposed" directive and apply all its usual effects, in adddition to giving your icon a black background (white didn't seem like a better choice??).
The solution is, of course, to precompile the icons with no transparency. This makes it pretty difficult to utilize Android's support of alpha channels while offering itouch icons as well if a black background does not work for you. I found this tool useful when composing: http://www.gieson.com/Library/projects/utilities/icon_slayer
Same issue seen here: How to get iOS to properly respect the "apple-touch-icon-precomposed" link attribute for a "web app"
Transparent Apple Touch Icons are indeed possible. What you need to do is strip all excess information from the PNG using ImageOptim for Mac https://imageoptim.com/mac or a similar program on windows. I did extensive research and stumbled on the answer by looking at the apple touch icon used by the Virtual DJ site. This icon keeps it's transparent background on iOS and MacOS Sierra. I looked at the file size and realized how small it was compared to the custom apple touch icons with transparency that I made for my favorites in Safari. Next I looked at the file information using the inspector in Mac's Preview app. All of my custom apple touch icons had four tabs in the inspector section named General, exif, PNG and TIFF. The virtual DJ icon only had two tabs named PNG and General. Once I ran my custom images through ImageOptim the file sizes plummeted by over 90% and the extra TIFF and exif tabs disappeared from the inspector in Preview. Sure enough once I reloaded my custom images and launched Safari all of my Favorites tabs have transparent backgrounds!!!! Please see attached image for proof. Transparent Apple-Touch-Icons
I'm trying to build a weather application on the iPad but it seems that I need some help in animation. Say I'm animating a Radar, so the radar source files have 10 gif/jpeg pictures in 900x700 pixel size. I've tried the UIImage animation technique using the tutorial here:
http://www.icodeblog.com/2009/07/24/iphone-programming-tutorial-animating-a-game-sprite/
but it seems that loading 10 images that big is too much for the iPad to handle and its crashing due to memory warnings. I'm researching other techniques to animate but I can't seem to find something that will do this efficiently.
I've looked at others like Core Animation using sprites, and Cocos2D with sprites. Can someone point in the right direction the best way to animate these big images? (keep in mind that these images are dynamic and changes often so the sprites will have to be recreated on a server and fetched from the iPad to do the animation). Thanks
OpenGL only creates textures with dimensions at powers of 2. In the case of your images, that's 1024x1024, which is a meg of memory per image. Still, that shouldn't be a problem with the iPad.
First, investigate using Xcode's profiling tools to ensure the images aren't being repeatedly loaded into memory at each loop of the animation (likely by way of new objects that aren't sharing cached textures). That could solve your problem from the start.
Second, I recommend using Cocos2D if only for the easy handling of textures and caching. Toss the images into a CCAnimation, pop that into a CCRepeatForever, run it with a CCSequence. When you're done hit CCTextureCache to release unused textures.
Third, lower your animation framerate to 30 or less (if only for this animation). It may be the iPad, but you making a weather app. Not a video game.
Finally, downgrade the size of your image. Justify all you want, but a large radar animation will not sell your app. And just because a website might already be playing that animation beautifully, remember that a desktop has vastly more memory and power than any smart phone.
Try breaking the animation image into into smaller parts and animate those instead by treating each components as sprites. It would be best if you use primarily code (CoreGraphics) and draw your radar "by hand" instead of just using images as if they were animated GIFs.
In a project that I am currently working on I have an transparent NSWindow overlayed on a QTMovieView. At certain points I slide a custom view into this child window with animation so that it is displayed over the movie for a short period of time. The only odd behavior is that the animation is smooth on a Mac Book Pro but on a Mac Book(Same OS-X Version) there is significant flicker. The flicker only occurs on the portion of the window that has the actual QTMovie behind it.
Has anyone seen this behavior before or found a way to work around it?
The older MacBooks don't have real video hardware and used shared memory, so it's probably an issue with a slow video card trying to update # 30fps. Have you tried smaller movies to see if the issue goes away?
You may be better off with a pipeline like in the QTCoreVideo101 sample code from Apple. That would be a bit more work, you'd have to take care of the animation yourself, but you would get ultimate control over what is being drawn.