I'm using UImagePickerController to take a photo from the camera on iOS9. Then I found that using writeImageToSavedPhotosAlbum to save the image is different from saving the image using UIImageJPEGRepresentation at the file size. Code as follow:
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)image editingInfo:(nullable NSDictionary<NSString *,id> *)info {
if( [picker sourceType] == UIImagePickerControllerSourceTypeCamera ) {
[picker dismissViewControllerAnimated:YES completion:nil];
UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];
ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
[library writeImageToSavedPhotosAlbum:image.CGImage orientation:(ALAssetOrientation)image.imageOrientation completionBlock:^(NSURL *assetURL, NSError *error ) {
// NSLog(#"url: %#", assetURL.absoluteString);
NSData *data1 = UIImageJPEGRepresentation(image, 1.0);
NSString *path = [NSString stringWithFormat:#"%#%#", NSTemporaryDirectory(), #"/tmp.jpg"];
[data1 writeToFile:path atomically:YES];
[library assetForURL:assetURL resultBlock:^(ALAsset *asset) {
ALAssetRepresentation *rep = [asset defaultRepresentation];
// CGImageRef iref = [rep fullResolutionImage];
NSLog(#"size1: %lu, size2: %lld", data1.length, rep.size);
} failureBlock:^(NSError *error) {
}];
}];
}
}
it prints:
2016-09-08 10:10:56.690658 TestPhotoes[6096:2345233] size1: 5549568, size2: 2288036
You see, the image file saved by UIImageJPEGRepresentation is way much bigger than by writeImageToSavedPhotosAlbum. I was wondering what the writeImageToSavedPhotosAlbum did? Does it compress the origin image? How can I save image using UIImageJPEGRepresentation to achieve the same effect, both image file size, and the image quality?
Related
I want is that when user pick the video from gallery i want to get the thumbnail image of the video.So is it possible to get the thumbnail image of the video without uploading it to server?
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
NSURL *urlvideo = [info objectForKey:UIImagePickerControllerMediaURL];
__block NSData *movieData = [[NSData alloc]initWithContentsOfURL:urlvideo];AVURLAsset *asset=[[AVURLAsset alloc] initWithURL:urlvideo options:nil];
AVAssetImageGenerator *generator = [[AVAssetImageGenerator alloc] initWithAsset:asset];
generator.appliesPreferredTrackTransform=TRUE;
CMTime thumbTime = CMTimeMakeWithSeconds(0,30);
AVAssetImageGeneratorCompletionHandler handler = ^(CMTime requestedTime, CGImageRef im, CMTime actualTime, AVAssetImageGeneratorResult result, NSError *error){
if (result != AVAssetImageGeneratorSucceeded) {
NSLog(#"couldn't generate thumbnail, error:%#", error);
}
UIImage *img = [UIImage imageWithCGImage:im];
};
}
I have some images in my Photo Album. I have already retrieved the asset urls of all of them.. I want to get a particular image using the asset url... below code gave me asset url..
ALAssetRepresentation *defaultRepresentation = [asset defaultRepresentation];
NSString *uti = [defaultRepresentation UTI];
NSURL *URL = [[asset valueForProperty:ALAssetPropertyURLs] valueForKey:uti];
Now using this url, how can I get the image(UIImage)?
Get Url by this,
NSURL *url= (NSURL*) [[asset valueForProperty:ALAssetPropertyURLs] valueForKey:[[[asset valueForProperty:ALAssetPropertyURLs] allKeys] objectAtIndex:0]];
And get image from url like below.
ALAssetsLibraryAssetForURLResultBlock resultblock = ^(ALAsset *myasset)
{
ALAssetRepresentation *rep = [myasset defaultRepresentation];
#autoreleasepool {
CGImageRef iref = [rep fullScreenImage];
if (iref) {
UIImage *image = [UIImage imageWithCGImage:iref];
self.loadedImage = image;
dispatch_async(dispatch_get_main_queue(), ^{
//UIMethod trigger...
});
iref = nil;
}
}
};
ALAssetsLibraryAccessFailureBlock failureblock = ^(NSError *myerror)
{
NSLog(#"Can't get image - %#",[myerror localizedDescription]);
};
ALAssetsLibrary* assetslibrary = [[ALAssetsLibrary alloc] init];
[assetslibrary assetForURL:yourUrl
resultBlock:resultblock
failureBlock:failureblock];
UIImage *img = [UIImage imageWithCGImage:[[myAsset defaultRepresentation] fullResolutionImage]
Hope this helps
Hi I am trying to buil and interface which gives user options to select an existing image or take new from camera. Selecting existing image works fine and I am able to get the image file name. But when I try to take new image I am able save image to library but can not get its file name. It returns nil. Here is my code:
- (void)imagePickerController:(UIImagePickerController *)picker
didFinishPickingMediaWithInfo:(NSDictionary *)info {
NSLog(#"Dismissing camera ui...");
[self.cameraUI dismissViewControllerAnimated:YES completion:nil];
NSLog(#"Getting media url...");
NSURL *mediaURL = [info objectForKey:UIImagePickerControllerMediaURL];
if(mediaURL) {
NSLog(#"This is a video = %#", mediaURL);
} else {
NSLog(#"This is a photo...");
NSLog(#"Getting media type...");
NSString *mediaType = [info objectForKey:UIImagePickerControllerMediaType];
NSLog(#"Selected mediaType : %#", mediaType);
UIImage *originalImage;
if (self.source == UIImagePickerControllerSourceTypeCamera) {
// Handle a still image capture
if (CFStringCompare ((CFStringRef) mediaType, kUTTypeImage, 0) == kCFCompareEqualTo) {
originalImage = (UIImage *) [info objectForKey:UIImagePickerControllerOriginalImage];
NSLog(#"Saving new image...");
if (self.source != UIImagePickerControllerSourceTypePhotoLibrary) {
UIImageWriteToSavedPhotosAlbum(originalImage, nil, nil , nil);
}
} else {
// Handle a movie capture
}
}
NSLog(#"Getting reference url...");
NSURL *referenceURL = [info objectForKey:UIImagePickerControllerReferenceURL];
ALAssetsLibrary *assetLibrary = [ALAssetsLibrary new];
[assetLibrary assetForURL:referenceURL
resultBlock:^(ALAsset *asset) {
ALAssetRepresentation *assetRep = [asset defaultRepresentation];
NSString *filename = [assetRep filename];
NSLog(#"File name = %#", filename);
if(self.selectedMediaNames == nil)
self.selectedMediaNames = [[NSMutableArray alloc] init];
[self.selectedMediaNames addObject:filename];
[self.tableView reloadData];
[self.activitIndicator stopAnimating];
[self.activitIndicator setHidden:true];
}
failureBlock:^(NSError *error) {
NSLog(#"%#", error);
}];
}
[[UIApplication sharedApplication] setStatusBarHidden:YES];
}
My goal is use this image name for upload the image to server.
I am still getting nil but I have solved my problem by saving image to a temp directory and use this path for upload:
NSString *path = [NSTemporaryDirectory()
stringByAppendingPathComponent:#"upload-image.tmp"];
NSData *imageData = UIImageJPEGRepresentation(originalImage, 1.0);
[imageData writeToFile:path atomically:YES];
This question already has answers here:
Getting image name of iphone photo library
(2 answers)
Closed 9 years ago.
I've searched how to get the name of the saved image takes from the camera, but i didn't find something simple.
this is my code :
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
if( [picker sourceType] == UIImagePickerControllerSourceTypeCamera){
UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];
[library writeImageToSavedPhotosAlbum:image.CGImage orientation:(ALAssetOrientation)image.imageOrientation completionBlock:^(NSURL *assetURL, NSError *error )
{
NSLog(#"IMAGE SAVED TO PHOTO ALBUM");
[library assetForURL:assetURL resultBlock:^(ALAsset *asset )
{
NSLog(#"we have our ALAsset!");
NSLog(#"%#", assetURL);
}
failureBlock:^(NSError *error )
{
NSLog(#"Error loading asset");
}];
}];
}
}
I you have the answer, i will happy to test it .
Thanks in advance.
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
NSURL *resourceURL;
[picker dismissViewControllerAnimated:YES completion:nil];
UIImage *image =[[UIImage alloc] init];
image =[info objectForKey:#"UIImagePickerControllerOriginalImage"];
NSURL *imagePath = [info objectForKey:#"UIImagePickerControllerReferenceURL"];
NSString *imageName = [imagePath lastPathComponent];
resourceURL = [info objectForKey:UIImagePickerControllerReferenceURL];
NSData *imageData;
NSString *extensionOFImage =[imageName substringFromIndex:[imageName rangeOfString:#"."].location+1 ];
if ([extensionOFImage isEqualToString:#"jpg"])
{
imageData = UIImagePNGRepresentation(image);
}
else
{
imageData = UIImageJPEGRepresentation(image, 1.0);
}
int imageSize=imageData.length/1024;
NSLog(#"imageSize--->%d", imageSize);
if (imageName!=nil) {
NSLog(#"imageName--->%#",imageName);
}
else
{
NSLog(#"no image name found");
}
}
If you are using ASSerts
-(void)assetPickerController:(WSAssetPickerController *)sender didFinishPickingMediaWithAssets:(NSArray *)assets
{
[self dismissViewControllerAnimated:YES completion:^{
if (assets.count < 1) return;
//self.pageControl.numberOfPages = assets.count;
int index = 0;
for (ALAsset *asset in assets) {
// NSString *imageName = [[asset defaultRepresentation] filename];
UIImage *image = [[UIImage alloc] initWithCGImage:asset.defaultRepresentation.fullScreenImage];
// (#"%#", [[asset defaultRepresentation] filename]);
NSData *imageData = UIImagePNGRepresentation(image);
int imageSize=imageData.length/1024;
(either)
NSURL *imagePath = [asset objectForKey:#"UIImagePickerControllerReferenceURL"];
// NSURL *imagePath = [NSURL URLWithString:[asset ob]];
NSString *imageName = [imagePath lastPathComponent];
(or)
NSLog(#"%#",[[asset defaultRepresentation] filename]);
index++;
}
}];
}
Try following code. I have used this in one of my previous project and its working for me :
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
_selectedImage = info[UIImagePickerControllerEditedImage];
self.photoView.image = _selectedImage;
NSURL *refURL = [info valueForKey:UIImagePickerControllerReferenceURL];
// define the block to call when we get the asset based on the url (below)
ALAssetsLibraryAssetForURLResultBlock resultblock = ^(ALAsset *imageAsset)
{
ALAssetRepresentation *imageRep = [imageAsset defaultRepresentation];
NSLog(#"[imageRep filename] : %#", [imageRep filename]);
};
// get the asset library and fetch the asset based on the ref url (pass in block above)
ALAssetsLibrary* assetslibrary = [[ALAssetsLibrary alloc] init];
[assetslibrary assetForURL:refURL resultBlock:resultblock failureBlock:nil];
[picker dismissViewControllerAnimated:YES completion:NULL];
}
I need to save path of the image picked from server and later access the path to show that image on user click by database retrival.
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
NSString *urlPath = [info objectForKey:#"UIImagePickerControllerReferenceURL"]absoluteString];
}
and saving it to database.
It saved as assets-library://asset/asset.JPG?id=E1136225-97DE-4BF4-A864-67E33D60737A&ext=JPG
then I want to import to Imageview
UIImageView *iv = [[UIImageView alloc]init];
iv.image = [UIimage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:imagepath]]];
But it is not working
Try this:
typedef void (^ALAssetsLibraryAssetForURLResultBlock)(ALAsset *asset);
typedef void (^ALAssetsLibraryAccessFailureBlock)(NSError *error);
ALAssetsLibraryAssetForURLResultBlock resultblock = ^(ALAsset *myasset){
ALAssetRepresentation *rep = [myasset defaultRepresentation];
CGImageRef iref = [rep fullResolutionImage];
if (iref){
UIImage *myImage = [UIImage imageWithCGImage:iref scale:[rep scale] orientation:(UIImageOrientation)[rep orientation]];
[fileImage addObject:myImage];
}
};
ALAssetsLibraryAccessFailureBlock failureblock = ^(NSError *myerror){
//failed to get image.
};
ALAssetsLibrary* assetslibrary = [[[ALAssetsLibrary alloc] init] autorelease];
[assetslibrary assetForURL:[filePath objectAtIndex:0] resultBlock:resultblock failureBlock:failureblock];
Note: Make sure your [filePath objectAtIndex:0] will be a NSUrl object. Else convert it to NSUrl
Example:
ALAssetsLibrary* assetslibrary = [[[ALAssetsLibrary alloc] init] autorelease];
NSURL myAssetUrl = [NSURL URLWithString:[filePath objectAtIndex:0]];
assetslibrary assetForURL:myAssetUrl resultBlock:resultblock failureBlock:failureblock];
Use assetForURL:resultBlock:failureBlock: method of ALAssetsLibrary class to retrieve image by URL.
There is more info: http://developer.apple.com/library/ios/#documentation/AssetsLibrary/Reference/ALAssetsLibrary_Class/Reference/Reference.html#//apple_ref/doc/uid/TP40009722
UPD:
ALAssetsLibrary *lib = [[ALAssetsLibrary alloc] init];
[lib assetForURL: url resultBlock: ^(ALAsset *asset) {
ALAssetRepresentation *r = [asset defaultRepresentation];
self.imgView.image = [UIImage imageWithCGImage: r.fullResolutionImage];
}
failureBlock: nil];
Where is url is your cached URL