I'm having trouble with the way iOS handles animated-GIF's. I know that you cannot use animated-GIF's on an UIImageView and you have to use custom animations on the UIImageView.
But..
I have a Java server that sends GIF images through a socketstream. The iOS (iPhone) receives that stream and converts it into an NSData type. I've succeeded in capturing and displaying this image in a UIImageView but as many of you already know.. it only displays the first frame.
I Also found some code to decode that GIF into separate images, but that code works from a GIF file and not NSData.
Question: How do i convert the NSData file into separate images and place them in an NSArray to use it as animation?
Note: In the NSData that is received are both an image and some text separated by a rare character. so the NSData looks like this: [image] [separator] [text].
Hope somebody can give me some pointers or some samples to work with..
Thanks in advance, i will keep searching untill you or me finds an answer :)
Unless you're targeting devices before IOS 4, use ImageIO.
NSMutableArray *frames = nil;
CGImageSourceRef src = CGImageSourceCreateWithData((CFDataRef)data, NULL);
if (src) {
size_t l = CGImageSourceGetCount(src);
frames = [NSMutableArray arrayWithCapacity:l];
for (size_t i = 0; i < l; i++) {
CGImageRef img = CGImageSourceCreateImageAtIndex(src, i, NULL);
if (img) {
[frames addObject:[UIImage imageWithCGImage:img]];
CGImageRelease(img);
}
}
CFRelease(src);
}
I made a wrapper that also handles animation time based on the code from Anomie
https://gist.github.com/3894888
Related
I fetched images from json and put all image url's in array, rather than calling json again. Now i don't know how to set the condition that it load images as table scrolled. Here is the method i called for this.
+ (NSMutableArray *) createImg: (NSArray*)sampleData
{
NSMutableArray *arrImg = [[NSMutableArray alloc]init];
for(int i=1; i<=[sampleData count]; i++)
{
NSString *strOfUrl = [sampleData objectAtIndex:i];
UIImage *img = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:strOfUrl]]];
if(img == NULL)
{
NSLog(#"null no image");
}
else{
[arrImg addObject:img];
}
}
return arrImg;
}
Please guide for the above and feel free to ask anything if not clear in this.
Thanks in advance.
I know this might not be exactly what you are looking for. However, I'd suggest you to use this AsyncImageView. It'll do all the logic you need for lazy loading. Also, it'll cache the images. To call this API:
ASyncImage *img_EventImag = alloc with frame;
NSURL *url = yourPhotoPath;
[img_EventImage loadImageFromURL:photoPath];
[self.view addSubView:img_EventImage]; // In your case you'll add in your TableViewCell.
It's same as using UIImageView. Easy and it does most of the things for you. AsyncImageView includes both a simple category on UIImageView for loading and displaying images asynchronously on iOS so that they do not lock up the UI, and a UIImageView subclass for more advanced features. AsyncImageView works with URLs so it can be used with either local or remote files.
Loaded/downloaded images are cached in memory and are automatically cleaned up in the event of a memory warning. The AsyncImageView operates independently of the UIImage cache, but by default any images located in the root of the application bundle will be stored in the UIImage cache instead, avoiding any duplication of cached images.
The library can also be used to load and cache images independently of a UIImageView as it provides direct access to the underlying loading and caching classes.
use this. It is perfect way to show images while scrolling:
https://github.com/enormego/EGOImageLoading
I am creating an app in which I am loading 800 jpg images for the Imageview.On occurance of different enevts different set of images are to be loaded for animation.on fire of first event it works fine but on 2nd event it crashes on iPhone.Any help?
my part of code is as below
for (int aniCount = 1; aniCount < 480; aniCount++){
UIImage *frameImage = [UIImage imageWithContentsOfFile: [[NSBundle mainBundle] pathForResource: [NSString stringWithFormat: #"ani_soft_whimper_%i", aniCount] ofType: #"jpg"]];
[_arr_ImagesSoftWhimper addObject:frameImage];
}
imageView.animationImages = _arr_ImagesSoftWhimper;
and i m getting crash for these set of images.
It is possible that you are running out of memory. But this is just a guess. Please provide some code.
1.if you are downloading from any server please call Asynchronous call.
2. check your image dimension,size,if dimension is big according to uiimageview frame then first resize or crop your image and then set into uiimageview.
I am learning Cocos2d and building an application where i have sprite at one end and I need to through it on the other side and with the same I am removing the sprite from the screen and after some time, I am displaying the same.
Now I have a folder of images in my application and I need to load different images each time in random order from the same folder and maintain a log that these images do not repeat again and again. I am able to load images from the folder with :
NSString *bundleRoot = [[NSBundle mainBundle] bundlePath];
NSArray *dirContents = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:bundleRoot error:nil];
NSArray *onlyJPGs = [dirContents filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:#"self ENDSWITH '.jpg'"]];
Now how would I call this array and display different images each time and also maintain a log that images don't get repeat. I have already went through links like this and this but in vail. Any clue will be really very helpful. Thank you for the help in advance.
The best way to do this is by creating a spriteSheet. first of all you can get http://zwoptexapp.com/ , its free and you can create your spritesheet for using with cocos (on the exporter make sure you select cocos2d to create the proper plist)
You want to pack all your image in 1 big texture so you can add it to your project with the plist (zwoptex will create both for you)
then you can load your texture with
[[CCSpriteFrameCache sharedSpriteFrameCache] addSpriteFramesWithFile:#"your_plist"];
switching textures is slow operation, so having all the images in the same texture will boost the openGL performance, after you've done that changing the texture for a sprite is very easy
[yourSprite setDisplayFrame:[[CCSpriteFrameCache sharedSpriteFrameCache] spriteFrameByName:#"FRAME_NAME"]];
where FRAME_NAME is the name of the frame in the plist (you can see it by selecting the plist inside xcode.
to cycle in a random way without repeating images...
(i'll write some pseudocode directly in here, let me do inits inside class declaration and inline implementations :) )
//WARNING THIS IS PSEUDO CODE :)
#interface Randomizer {
//an array of NSStrings containing all you images names
NSMutableArray *allImagesFrameNames = [NSMutableArray arrayWithCapacity:NUM_FRAMES];
CCSprite *sprite = alloc init
}
-(void) resetAllFrames {
[allImagesFrameNames removeAllobjects];
[allImagesFrameName addObject:#"FIRST_IMAGE"];
[allImagesFrameName addObject:#"SECOND_IMAGE"]; //add all your images
}
#end
And to display a random frame:
-(void) display a randomImage {
//if the array is empty, all images are already been randomly displayed, so we reset the array
if([allImagesFrameName count] == 0)
[self resetAllFrames];
//we choose a random index
int randomIndex = arc4random %[allImagesFrameName count];
//we get the frame name at that index
NSString *imageFrameName = [allImagesFrameNames objectAtIndex:randomIndex];
//and we display the frame
[sprite setDisplayFrame:[[CCSpriteFrameCache sharedSpriteFrameCache] spriteFrameByName:imageFrameName]];
[allImagesFrameNames removeObjectAtIndex:randomIndex];
}
Im attempting to save some images to a camera roll, all the images are in a array.
if (buttonIndex == 1) {
int done = 0;
NSMutableArray *copyOfImages = [[NSMutableArray alloc]initWithArray:saveImagesToArray];
while (!done == 1){
if (copyOfImages.count == 0) {
done = 1;
}
if (copyOfImages.count > 0){
[copyOfImages removeLastObject];
}
UIImage *image = [[UIImage alloc]init];
image = [copyOfImages lastObject];
UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);
}
}
because i dont know how many images there can be i use a while loop
Im testing this with 8 images, the array shows a count of 8 so thats good.
When i try saving the images this comes up in the console.
-[NSKeyedUnarchiver initForReadingWithData:]: data is NULL
Out of the 8 images im trying, only 5 show up in the camera roll.
Any help would be great.
Thanks :)
Why are you calling [copyOfImages removeLastObject]?
Every time you go through that look are you destroying the last object, which is strange because you haven't added it to the roll yet. Take out that line and see if you look works.
Also, rather than using a for loop, use the following pattern:
for (id object in array) {
// do something with object
}
This will enumerate though the objects in the array, stopping when it reaches the end. Just be sure not to modify the array while you are doing this.
I had this same issue and I resolved it by ensuring that the images are saved sequentially. I think there may be some kind of race condition going on.
Basically, I did:
UIImageWriteToSavedPhotosAlbum([self.images objectAtIndex:self.currentIndex], self,
#selector(image:didFinishSavingWithError:contextInfo:), nil);
Then in image:didFinishSavingWithError:contextInfo:, I increment currentIndex and try the next image, if there are any left.
This has worked for me in every case so far.
I had the same exact problem. No matter how much pictures i added to the share activityController, maximum of 5 were saved.
i have found that the problem was to send the real UIImage and not URL:
NSMutableArray *activityItems = [[NSMutableArray alloc] init];
for(UIImage *image in imagesArray) {
[activityItems addObject:image];
}
UIActivityViewController *activityController = [[UIActivityViewController alloc] initWithActivityItems:activityItems applicationActivities:nil];
To expand on Bill's answer, UIImageWriteToSavedPhotosAlbum seems to do its writing on some unknown thread asynchronously - but also there is some hidden limit to the number of images it can write at once. You can even tease out write busy-type errors if you dig in deep.
Tons more info here:
Objective-C: UIImageWriteToSavedPhotosAlbum() + asynchronous = problems
I also agree with Bill that serializing your writes is the only reasonable/reliable answer
I have seen.
I have a sequence of images needed to display in a short time (PNG sequence). There are totally 31 PNGs in total, each with file size about 45KB. I have already loaded them with the following codes:
imgArray = [[NSMutableArray alloc] init];
for(int i = 0; i <= 30; i++) {
NSString * filename = [NSString stringWithFormat:#"img_000%.2d.png", i];
UIImage *temp = [UIImage imageNamed:filename];
[imgArray addObject:temp];
[temp release];
temp = nil;
}
I use the following codes for displaying the images:
CGImageRef image = [(UIImage *)[imgArray objectAtIndex:imgFrame] CGImage];
imgLayer.contents = (id)image;
if(imgFrame < 29) {
imgFrame++;
} else {
imgFrame = 0;
imgLayer.hidden = TRUE;
[imgTimer invalidate];
}
where imgLayer is a CALayer. (imgTimer is a repeating timer with interval 0.03s)
But I found that when I call the images out, it is very laggy at the first time. Except the 1st appearance, other appearance has no problem.
Is it related to preloading images? Or are my images too big in file size?
The reason for your lags are hard to tell without profiling data. But here is a trick that might help: Join all your images into one large file. Try to make it rectangular (maybe 6x6 in your case or 4*8). Then load this single file and crop each image out for display (i.e. create an image for display with the size of a tile and copy one tile from the big image after the other into the display image).
Images are loaded when they are used and displayed.
If you use the time profiler in Instruments, you will the lag you're experiencing. If you then zoom to that lag and look at what is causing it, you will usually see that "copyImageBlockSetPNG" is the function taking time, right before "inflate".
What you must find a way to do is create your images and force load them before you need them. That's another story apparently.