I have some graphics I want to import into iPhone application. They are people / animals from photos that I cropped out that so they have transparent backgrounds. Obviously, I can't use JPEG as is traditionally recommended for photos because of transparency so what would be the second best option? I'm currently using png-24, but I assume that's too big. Is gif OK? Or something else?
It is recommended by Apple to use PNG whenever possible. PNG is still a compressed format so I think you'll be fine with respect to size.
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What would be the best advice if I have my app built with SD images but I want it to look decent on iphone devices that support HD?
I've heard that simply doubling the size of all my images to get HD versions using Photoshop doesn't look good?
If I just don't support HD at all (turn retina display off in cocos2d) will it look blurred?
There are two types of source images: the raw graphics files you used to create your images, such as a Photoshop or Illustrator file, and then the actual images you exported from those programs to include in your app.
For example, you might take a 10 megapixel photo with a digital camera, but you size it down to include it in your app.
You do not want to increase the size/resolution of the pictures you exported for the app, because they do not have the graphic information to fill a higher image. It's like take a cup of water and expecting it to fill a bucket. The information is simply not there and it will look bad.
However, if you go back to your original graphics files, such as the 10 megapixel image in my example, you can create a new set of exported graphics for the higher resolution. You always start with your raw source files and then go down from there. Never start with files already exported for a certain resolution and then try to go up from there, or you will have pixelated poor graphics as the result.
I have developed one game for iphone which uses png images.It works well but which are the vector graphics images supported by iphone that i can use for my game for better quality of image like when we zoom the image the image displayed properly.which are the most common image formats that are widely used by iphone game developers?
I saw this on github a while back. It claims to render SVGs to Core Image layers. I've never used it, but I know it exists.
The only vector graphics format that is directly supported on iOS is PDF (not counting UIWebView, which also supports SVG).
Vector graphics are not typically used in games, because they're much slower to render, but that depends on what type of game you're developing. I would consider using multiple versions of bitmap images with different resolutions for zooming.
I'm about to start a new iphone/ipad project which required a library of images. I've been trying to find if there are any pieces of software which would automatically resize images and save them in the right format for iphone and ipad... no such luck as yet!
So, I have large images of all different sizes. I need to create three images from each one.
iPad, iPhone (high res), iPhone (normal res)
I was thinking of recording something in Photoshop, but wondered if there's anything out there which already does this? My trouble is that I need to resize based on either the width or the height (which ever is larger).
Thanks for any tips!
Unless all your graphics are rasterized it might be better to do the resizing through Photoshop, that way you don't lose the pretty vector resizing. In Photoshop, I'd recommend checking out Export Layers to Files and Layer Comps to Files under File>Scripts. They've both proven invaluable while dealing with massive image libraries for universal apps.
How about some batch image resizer freeware, like this?
http://www.fotosizer.com/
Is it true that we have to use png images for development in iPhone and iPad. What is the advantage we would gain when using png images?
Apple has said that Xcode will optimize PNGs during the build process.
This article explains exactly what it is doing, and why PNGs are preferred over other formats on the iPhone. In other words, you will lose performance by using any other formats, as the conversion must be done at runtime.
http://iphonedevelopment.blogspot.com/2008/10/iphone-optimized-pngs.html
You dont have to use png. You can use gif, jpeg, and others. If you use png, xcode will optimize them for the iOS loader (changes the byte-order of some data in the png; I'm not clear on this exactly) resulting in faster loading images.
PNG supports alpha transparency (GIF only support transparent pixels, not semi-transparent) and the quality is good (not like JPEG).
It also supports loseless compression.
This similar question goes over this: When to use PNG or JPG in iPhone development?
Pngs are a lossless format so for design, buttons, etc... for iphone/ipad what you see in photoshop (or whatever) is going to be exactly what you get as opposed to jpegs which use compressions.
That post also said that pngs use less processor to be displayed since they are uncompressed.
#Krishnan the main advantage of using the png images is they are very light weighted......and as u know memory management is a very big issue in iphone and ipad development...thats why we use them....and for more detailed information look here
A question for the seasoned iPhone developers, what is your preference for graphics in an iPhone app? I have turned to PNGs because I read that is the preferred image format and they are the most efficient format for the OS in terms of performance. However I had read you should try to use svg graphics so they scale up on the iPad. I started reading up on svg for my next app and thought the format was natively supported by UIImageView, but it seems you can only render them in UIWebviews or programatically. My belief was a lot of the latest graphically-rich apps used svg graphics, is that an incorrect assumption?
Thanks for any advice/comments.
I think using SVG graphics would cause a ton of problems and I'm not aware of any apps that use it. It's probably a much better idea to use PNGs and just have different sizes for iPhone, iPhone 4 and iPad.