I've created some avatars from vector artwork and saved them as transparent PNGs. If I place the PNGs in interface builder, the quality is perfect. When I place them using code, the edges are horribly jagged, as if the AA has been removed, yet it's the same image. Is there any way to place them with code and maintain nice smooth edges?
I've attached a screenshot below with the iphone ver on the right.
Thanks,
Chris
Apple compresses pngs using a special optimization formula. It is possible that this formula is causing your images to alter from the original. If you notice a difference that you cannot live with, turn off the optimization by going into your target's info panel and unchecking the Compress PNG files option under the build tab.
I have the same experience with this kind of situation.
Also when I change the hardware to iphone 4 it seems to be really good. so my suggestion to u is that unless u transfer ur app to iphone dont relay on the simulator.
You cannot really tell what will be the result on iphone by referring to simulator.
so dont panic, just check the image on iphone first before you get to any conclusion.
Related
Images that I add to the layer in Cocos2d look pixelated around the edges of the image (i.e. a hillside, the rounded part of the hill, where the sky and the hill meet). I don't know if it's the image quality, or just because the graphics processor on my 'older' MacBook Pro is not as advanced as the iPhone 4 or iPod Touch 4 or iPad 2. Is it because of that?
I have ran into an instance where a large resolution image was being used in the context of a locally packaged HTML file in a UIWebView. The image looked fine in the simulator, but when ran on a hardware device, a bug was exposed in the rendering engine where it would invert the colors. Here's a bug report as an example of this. The solution was to scale the image down a bit in photo editing application.
While an extreme corner case, this is an example of the simulator not quite living up to how things will work on a hardware device.
The simulator usually does a pretty good job representing what the final image will look like. For the image quality on a normal computer to be worse than that of an iPhone for it to make a large enough difference, your MacBook Pro has to be really bad. So I doubt it.
However, if you really want to make sure, the best way to check would be to transfer the image you are using to another machine to see if it still looks pixelated. If it does, its a problem with your image.
Hope this helps and good luck!
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/
Apple recommends cropping out the status bar from screenshots submitted to the app store. Doing this manually in Preview is a very tedious and error-prone process.
Do any developers have any best-practices recommendations or automated techniques for speeding up this process? The goal would be to take as input iPad and/or iPhone screenshots, and output them with the toolbar cropped off. We need to support both portrait and landscape orientation, and Retina-resolution iPhone screens.
I've found a few utilities online that purport to help with this, but the ones I have found seem to fail on Retina-display resolution screens. And another that works via the iOS Simulator requires a 1920x1080 resolution monitor to process iPad screenshots - making it useless for non-17" laptop-based developers.
Any other recommendations for taking good screenshots for the AppStore? I know (based on my searching) that there are a lot of other developers who would be interested in a quicker workflow to handle this.
Bonus points for being able to bulk-process an entire directory.
I developed a free App, Status Barred which is on the Mac App Store. It crops your iOS screenshots from iPhone, iPad, portrait, landscape, normal & retina display.
I used the ImageMagick command line tools to batch crop all the Screenshot png files, but haven't figured out how to not use auto assigned output filenames.
convert Screenshot*.png -crop 640x920+0+40 920Screenshot.png
Here are two ways, assuming you mean status bar and not toolbar (which you probably shouldn't crop out of the screenshots).
If you have photoshop, just change the canvas size by subtracting 20 (low-res) or 40 (retina) and anchoring the bottom of the image. This works perfectly.
It's also easy in iPhoto using the Edit/Crop feature. Set the dimensions to the correct size (Portrait: 320x460 or 640x920 and Landscape: 480x300 or 960x600) and move the crop screen to the bottom of the image. This does it perfectly as well.
After much searching, the easiest tool I have found is the iOS Simulator Cropper. It does a great job of handling different resolutions and orientations, and it is painless to use. No need to muck around with Photoshop or other slow / cumbersome tools.
Link: http://www.curioustimes.de/iphonesimulatorcropper/index.html
The developer reports that they have enhanced the iOS Simulator Cropper to bulk process screenshots taken on device as well as via the Simulator. I haven't tried this yet since the update, but if it works well this will be the perfect solution.
I have also found a very useful tool in the Mac App store called "Status Barred" that also very simply crops the status bar out of any images handed to it.
How about just using Preview? Command+A to select all, drag the selection down to 920px then Tools => Crop.
For example, preparing a launch screen of 320 x 480 would have to be changed....
How is that going to work for us? Are programmers always going to have to be submitting a high-res that will be scaled down for old devices such as the iphone 3g?
The size of the screen is basically 4 times on a pixel by pixel basis. So each pixel of your image for example gets boosted to 4.
What this means for you? You don't have to change your App, your app will scale to the hi res screen for you, same with your UI and images within your UI. Of course if you want to take advantage of the better screen quality you will have to submit hi res images.
I haven't looked at going the other way but I believe it would be a similar case.
One exception to this is text. It automatically scales to the higher res for you for free. So text will look super sharp. One problem with this is if your loading image has text based on the original load screen that wouldn't look the same as when the high res text loads.
Strictly speaking, anyone who's seen the documentation on how they're handling this is still under non-disclosure until Monday, when the new iOS ships.
Suffice to say, it's clever. You'll be able to put both high and low-rez versions of ALL your images into your app, and then load them into your app in a way that's totally transparent from the code side. The device will make its own call about which version of the image is appropriate for the kind of screen it's got.
Now that the WWDC 2010 videos are available for free to any registered iPhone developer (or ADC member), I recommend watching Session 134: Optimize your iPhone App for the Retina Display for a full description of what you need to do to support the iPhone 4's new display.
I'm developing an iPhone app. A simple image is the background of the main view.
I've set an UIImageView in the background and set an image in, using IB.
the image is a 160dpi PNG image. It appears like CRAP in IB. When running in the simulator it is ok, crisp.
How am I supposed to work and place my controls precisely on a such poor resolution image ?
Is this a bug ?
Thanks for you help!
IB is not a tool for designing a UI, it is a tool for implementing one. It is designed to perform well rather than display well (this is more important in complex desktop UI design than mobile but the tool is the same for both). The best advice is perhaps to take a cue from the publishing world (where this is a common practice for applications that display large amounts of high resolution graphics such as Adobe InDesign) and keep track of exact measurements for controls - the x,y coordinate positions and height/width. Then you can use the inspector to precisely position controls.
Actually, the DPI is not irrelevant at all.
Change the DPI to 72 and the image will display in IB/Xcode fine.
I don't see anything like this when I work with images in IB. Maybe there's something special about your PNG file? You say that it's 160 dpi, which is fairly irrelevant. More important are what its pixel diomensions are, and how they compare to the screen size.
Maybe the UIImageView is having trouble rendering your PNG, and is for some reason using the preview icon instead? Try a different image, or try resizing your image to 480x320, with 32-bit color.
I am wondering about this as well. I don't think the DPI of the image is what is doing this, because I have a project where everything looks fine in IB on one machine, then on my laptop, it displays the way the OP is describing.
The image dimensions are the same as the iPhone screen and the view dimensions (320x480), but the image displays all tiny instead of filling up the whole dimeal nsions of the UIImageView. If I scale to fill, then the image gets all blurry, at 320x480, even though I can confirm that those are the actual dimensions of the image... It's acting as if the image itself is 320x480 of empty space with a small version of my image centered inside it... this is very strange. As I said- this is the same project that looks completely fine in IB on another machine (and when they build, they both look normal in the simulator). This also happens on my friends's macbook.
Is there some setting in IB that might be the difference?
EDIT:
Guess I spoke too soon- I went back to my other machine and noticed the same problem this time, and it indeed was the dpi. This must have been a change in one of the recent updates to xcode/IB, because I originally never saw this issue, and the image files are exactly the same... strange.