I'm converting an image that I retrieved from a URL to base 64 using this code.
NSURL* imageUrl = [NSURL URLWithString:url];
NSData* urlData = [NSData dataWithContentsOfURL:imageUrl];
UIImage* uiImage = [UIImage imageWithData: urlData];
NSData* imageData = UIImagePNGRepresentation(uiImage);
NSData* base64 = [imageData base64EncodedDataWithOptions:0];
return [NSString stringWithUTF8String:[base64 bytes]];
the image url: https://api.qrserver.com/v1/create-qr-code/?data=somedata&size=220x220&margin=0
the generated base64 image.
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
I figured out the image is only halved because I checked using this tool.
http://codebeautify.org/base64-to-image-converter
Is there anyway I can generate a base64image String that contains the whole image?
In terms of why it's getting cut off, I suspect you're looking at the base64 string in the debugger, which will truncate it. Actually NSLog the string and you'll see it's longer than what you're seeing in the debugger.
A couple of other unrelated observations:
You should not use stringWithUTF8String with [base64 bytes] because the NSData will not be null terminated. If you really needed to convert it to a string, you'd use initWithData rather than stringWithUTF8String:
return [[NSString alloc] initWithData:base64 encoding:NSUTF8StringEncoding];
As others have pointed out, you can bypass the creation of the NSData of the base64 altogether, and create the string directly:
return [imageData base64EncodedStringWithOptions:0];
I'm not sure why you're taking the NSData from the server and round tripping it through a UIImage at all. You can theoretically just encode the data from the server directly:
NSURL* imageUrl = [NSURL URLWithString:url];
NSData* urlData = [NSData dataWithContentsOfURL:imageUrl];
return [urlData base64EncodedStringWithOptions:0];
The server is already returning you the NSData of a PNG representation. You don't need to do that UIImage and UIImagePNGRepresentation stuff at all. You're actually generating a PNG that is considerably larger than the one the server returned to you.
I'd advise against using dataWithContentsOfURL, because that's a synchronous network call. You probably should use NSURLSession and change this to be an asynchronous method.
NSURL* imageUrl = [NSURL URLWithString:#"https://api.qrserver.com/v1/create-qr-code/?data=somedata&size=220x220&margin=0"];
NSData *data = [NSData dataWithContentsOfURL:imageUrl];
UIImage *image = [UIImage imageWithData:data];
NSString *base64 = [self encodeToBase64String:image];
To convert your image to base64 String use following code:
- (NSString *)encodeToBase64String:(UIImage *)image {
return [UIImagePNGRepresentation(image) base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
}
That base64 will give you full image. Tested with your given image
Here is base 64 :
https://gist.github.com/anonymous/6d76e3ad852b4879ab097e6a1b3e68a2
To convert your UIImage into base64 string you can use this code.
NSString *base64String = [UIImagePNGRepresentation(uiImage) base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
Here is the code.
NSURL* imageUrl = [NSURL URLWithString:#"https://api.qrserver.com/v1/create-qr-code/?data=somedata&size=220x220&margin=0"];
NSData* urlData = [NSData dataWithContentsOfURL:imageUrl];
UIImage* uiImage = [UIImage imageWithData: urlData];
NSString *base64String = [UIImagePNGRepresentation(uiImage) base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
NSLog(#"%#",base64String);
I checked the result string on http://codebeautify.org/base64-to-image-converter
Try it, Hope it helps.
This is working perfectly
UIImage *img = [UIImage imageNamed:#"QRcode.png"];
NSString *base64 = [UIImagePNGRepresentation(img)base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
NSLog(base64);
The printed base64 String can be converted back to image in the URL you provided
Related
I am using vector graphics in my application and want to store some on Parse.com. I need to first convert these to NSData before upload. Is it possible to convert a pdf file to NSData?
UIImage *image = [UIImage imageNamed:#"coolImage.pdf"];
NSData *data = UIImageJPEGRepresentation(image);
I know NSData allows for a jpg of png representation but what about pdfs? Any tips on this would be greatly appreciated!
//to convert pdf to NSData
NSString *pdfPath = [documentsDirectory stringByAppendingPathComponent:#"test.pdf"];
NSData *myData = [NSData dataWithContentsOfFile:pdfPath];
I am unable to load an image because of nil returned by NSURL. The url looks like this : http://www.example.fr/wp-content/uploads/2014/06/préliminaire.jpg. When I enter my URL on firefox, I get my image but when I try in firefox the encoder http://www.example.fr/wp-content/uploads/2014/06/pr%3Flinaire.jpg I have no image...
Here is the code I use to load my image :
NSString *myString = #"http://www.example.fr/wp-content/uploads/2014/06/préliminaire.jpg";
NSURL *url = [NSURL URLWithString:myString];
NSData *data = [NSData dataWithContentsOfURL:url];
UIImage *img = [[UIImage alloc]initWithData:data];
That returns nil for url, so everything after is nil..
Thank you for your help guys
That's because those characters are not valid in a URL. Escape them first:
NSString *escaped = [myString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL *url = [NSURL URLWithString:escaped];
// etc.
I am trying to convert binary to NSData, and I am able to get data but uiimage is still nil. Below is my code. Please can anyone help me on this.
NSData *data = [self dataFromBase64EncodedString:[dictionary objectForKey:#"object"]];
UIImage *image = [UIImage imageWithData:data];
-(NSData *)dataFromBase64EncodedString:(NSString *)string{
if (string.length > 0) {
NSString *data64URLString = [NSString stringWithFormat:#"data:;base64,%#", string];
NSData *data = [NSData dataWithContentsOfURL:[NSURL URLWithString:data64URLString]];
return data;
}
return nil;
}
Your url seems to be missing the base url.
NSString *data64URLString = [NSString stringWithFormat:#"data:;base64,%#", string];
NSData *data = [NSData dataWithContentsOfURL:[NSURL URLWithString:data64URLString]];
Based on the above.. the url is set to "data:;base64,
shouldnt it be something like "http://my.server.com/imageurl"
I am trying to load in a very large string that is a base64 encoded PNG into NSData to create a UIImage on the fly. I can get the image generated by it is very distorted. Am I doing this correctly? I am also using SBJson in this example.
// Data is the NSData loaded in from the web
NSString *responseValue = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSString *successData = [(NSDictionary*)[responseValue JSONValue] objectForKey:#"MapFlightResult"];
NSData *pngData = [[NSData alloc] initWithBase64EncodedString:successData options:1];
UIImage *map = [UIImage imageWithData:mapData];
[imageView setImage:map];
I believe you issue is that your not sending in a base64 encoded string to initWithBase64EncodedString.
I'm trying to initialize an UIImage via URL.
This is the code I wrote:
NSString * path = [NSString stringWithFormat:#"%#",[[_tours objectAtIndex:indexPath.row]objectForKey:#"map_url"]];
NSURL *url = [NSURL URLWithString:path];
NSData *data = [NSData dataWithContentsOfURL:url];
UIImage *img = [[UIImage alloc]initWithData:data];
[[cell tourPreviewImage]setImage:img];
....
An example map_url looks like the following:
https://maps.google.com/maps/api/staticmap?size=200x200&maptype=roadmap&markers=size:big|color:green|72.3601030185,41.4626763775&markers=size:big|color:red|45.4563468516,94.4774796973&sensor=false
It seems that the NSURL Object cant handle the | Pipe Character the right way because i dont get any image data. If I delete the parameters separated by the pipe out of the url everything works fine.
Any Ideas how to solve this problem?
ok i found a solution for this. Encoding is what did go wrong.
NSString * path = [NSString stringWithFormat:#"%#",[[_tours objectAtIndex:indexPath.row]objectForKey:#"map_url"]];
path = [path stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL *url = [NSURL URLWithString:path];
NSData *data = [NSData dataWithContentsOfURL:url];
UIImage *img = [[UIImage alloc]initWithData:data];
[[cell tourPreviewImage]setImage:img];