I did some research and found that I should be able to convert a PDF into a byte[] and then into a UIImage but so far no luck. The reason for not being able to use CoreGraphics is that I'm using apportable which does not support the CGPDF classes.
I'm able to create a NSData object that seems to contain the PDF but when using that object to create a UIImage the image is nil.
- (instancetype) initWithBackSize: (CGSize) size
{
NSString *path = [[ NSBundle mainBundle ] pathForResource:#"pdfTest.pdf" ofType:nil ];
NSData* pdfData = [NSData dataWithContentsOfFile:path];
UIImage* image = [[UIImage alloc] initWithData:pdfData];
CCTexture* texture = [[CCTexture alloc] initWithCGImage: image.CGImage contentScale: image.scale];
self = [super initWithTexture: texture];
return self;
}
The binary data within a PDF file cannot be translated directly into an UIImage type. You need to find a third party library or some other way of converting a PDF file into an UIImage.
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I'm working on creating and storing OpenGL ES1 3D models, and want to include image files to be used as textures, within the same file as the 3D model data. I am having trouble loading the image data in a usable format. I'm using UIImageJPEGRepresentation to convert the image data and store it into an NSData. I then append it to a NSMutableData object, along with all the 3D data, and write it out to a file. The data seems to write and read without error, but I encounter problems when trying use the image data to create a "CGImageRef" which I use to generate the texture data for the 3D model. The image data seems to be in an unrecognized format after it is loaded from the file, because it generates the error "CGContextDrawImage: invalid context 0x0.” when I attempt to create the "CGImageRef". I suspect that the image data is gettin misaligned somehow, causing it to be rejected when attempting to create the "CGImageRef". I appreciate any help. I'm stumped at this point. All of the data sizes and offsets add up and look fine. Saves and loads happen without error. The image data just seems off a bit, but I don't know why.
Here's my code:
//======================================================
- (BOOL)save3DFile: (NSString *)filePath {
// load TEST IMAGE into UIIMAGE
UIImage *image = [UIImage imageNamed:#“testImage.jpg"];
// convert image to JPEG encoded NSDATA
NSData *imageData = UIImageJPEGRepresentation(image,1.0);
// Save length of imageData to global "imDataLen" to use later in “load3DFile”
imDataLen = [imageData length];
// TEST: this works fine for CGImageRef creation in “loadTexture”
// traceView.image=[UIImage imageWithData:[imageData subdataWithRange:NSMakeRange(0, imageDataLen)]];
// [self loadTexture];
// TEST: this also works fine for CGImageRef creation in “loadTexture”
// traceView.image=[UIImage imageWithData:txImData];
// [self loadTexture];
fvoh.fileVersion = FVO_VERSION;
fvoh.obVertDatLen = obVertDatLen;
fvoh.obFaceDatLen = obFaceDatLen;
fvoh.obNormDatLen = obNormDatLen;
fvoh.obTextDatLen = obTextDatLen;
fvoh.obCompCount = obCompCount;
fvoh.obVertCount = obVertCount;
fvoh.obElemCount = obElemCount;
fvoh.obElemSize = obElemSize;
fvoh.obElemType = obElemType;
NSMutableData *obSvData;
obSvData=[NSMutableData dataWithBytes:&fvoh length:(sizeof(fvoh))];
[obSvData appendBytes:obElem length:obFaceDatLen];
[obSvData appendBytes:mvElem length:obVertDatLen];
[obSvData appendBytes:mvNorm length:obNormDatLen];
[obSvData appendBytes:obText length:obTextDatLen];
[obSvData appendBytes:&ds length:(sizeof(ds))];
// next, we append image data, and write all data to a file
// seems to work fine, no errors, at this point
[obSvData appendBytes: imageData length:[imageData length]];
BOOL success=[obSvData writeToFile: filePath atomically:YES];
return success;
}
//======================================================
- (void) load3DFile:(NSString *)filePath {
NSData *fvoData;
NSUInteger offSet,fiLen,fhLen,dsLen;
[[FileList sharedFileList] setCurrFile:(NSString *)filePath];
fvoData=[NSData dataWithContentsOfFile:filePath];
fiLen=[fvoData length];
fhLen=sizeof(fvoh);
dsLen=sizeof(ds);
memcpy(&fvoh,[fvoData bytes],fhLen);offSet=fhLen;
//+++++++++++++++++++++++++++++++
obVertDatLen = fvoh.obVertDatLen;
obFaceDatLen = fvoh.obFaceDatLen;
obNormDatLen = fvoh.obNormDatLen;
obTextDatLen = fvoh.obTextDatLen;
obCompCount = fvoh.obCompCount;
obVertCount = fvoh.obVertCount;
obElemCount = fvoh.obElemCount;
obElemSize = fvoh.obElemSize;
obElemType = fvoh.obElemType;
//+++++++++++++++++++++++++++++++
memcpy(obElem, [fvoData bytes]+offSet,obFaceDatLen);offSet+=obFaceDatLen;
memcpy(mvElem, [fvoData bytes]+offSet,obVertDatLen);offSet+=obVertDatLen;
memcpy(mvNorm, [fvoData bytes]+offSet,obNormDatLen);offSet+=obNormDatLen;
memcpy(obText, [fvoData bytes]+offSet,obTextDatLen);offSet+=obTextDatLen;
memcpy(&ds, [fvoData bytes]+offSet,dsLen);offSet+=dsLen;
// the following seem to read the data into “imageData” just fine, no errors
// NSData *imageData = [fvoData subdataWithRange:NSMakeRange(offSet, imDataLen)];
// NSData *imageData = [fvoData subdataWithRange:NSMakeRange((fiLen-imDataLen), imDataLen)];
// NSData *imageData = [NSData dataWithBytes:[fvoData bytes]+offSet length: imDataLen];
NSData *imageData = [NSData dataWithBytes:[fvoData bytes]+(fiLen-imDataLen) length: imDataLen];
// but the contents of imageData seem to end up in an unexpected format, causing error:
// “CGContextDrawImage: invalid context 0x0.” during CGImageRef creation in “loadTexture”
traceView.image=[UIImage imageWithData:imageData];
[self loadTexture];
}
//======================================================
- (void)loadTexture {
CGImageRef image=[traceView.image].CGImage;
CGContextRef texContext;GLubyte* bytes=nil;GLsizei width,height;
if(image){
width=(GLsizei)CGImageGetWidth(image);
height=(GLsizei)CGImageGetHeight(image);
bytes=(GLubyte*) calloc(width*height*4,sizeof(GLubyte));
texContext=CGBitmapContextCreate(bytes,width,height,8,width*4,CGImageGetColorSpace(image),
kCGImageAlphaPremultipliedLast);
CGContextDrawImage(texContext,CGRectMake(0.0,0.0,(CGFloat)width,(CGFloat)height),image);
CGContextRelease(texContext);
}
if(bytes){
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_CLAMP_TO_EDGE);
glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA,width,height,0,GL_RGBA,GL_UNSIGNED_BYTE,bytes);
free(bytes);
}
}
//======================================================
I failed to receive any answers to this question. I finally stumbled across the answer myself. When I execute the save3DFile code, instead of adding the image data to NSMutableData *obSvData, using 'appendBytes' as illustrated below:
[obSvData appendBytes: imageData length:[imageData length]];
I instead use 'appendData' as shown here:
[obSvData appendData: imageData];
where imageData was previously filled with the contents of a UIImage and converted to JPEG format in the process as follows:
NSData *imageData = UIImageJPEGRepresentation(image,1.0);
See the complete code listing above for context. Anyway, the using 'appendData' instead of 'appendBytes' made all the difference, and allowed me to store the image data in the same file along with all the other 3D model data (vertices, indices, normals, et cetera), reloading all that data without problem, and successfully create 3D models with textures from a single file.
let image_data = UIImageJPEGRepresentation(self.imagetoadd.image!,0.0)
The image in ios, am using swift 3 to do this is being uploaded rotated.How can I solve such thing?
JPEG images usually contain an EXIF dictionary, here are stored a lot information about how the image was taken, image rotation is one of it.
UIImage instances keeps these information (if the original image has it) as well inside a specific property called imageOrientation.
As far as I remember this information is ripped of by using the method UIImageJPEGRepresentation.
To create a correct data instance with the above information you must use Core Graphics methods, or normalize the rotation before sending the image.
To normalize the image something like that should be enough:
CGImageRef cgRef = imageToSave.CGImage;
UIImage * fixImage = [[UIImage alloc] initWithCGImage:cgRef scale:imageToSave.scale orientation:UIImageOrientationUp];
To keep the rotation information:
CFURLRef url = (__bridge_retained CFURLRef)[NSURL fileURLWithPath:path];//Save data path
NSDictionary * metadataDictionary = [self imageMetadataForPath:pathToOriginalImage];
CFMutableDictionaryRef metadataImage = (__bridge_retained CFMutableDictionaryRef) metadata;
CGImageDestinationRef destination = CGImageDestinationCreateWithURL(url, kUTTypeJPEG, 1, NULL);
CGImageDestinationAddImage(destination, image, metadataImage);
if (!CGImageDestinationFinalize(destination)) {
DLog(#"Failed to write image to %#", path);
}
Where the -imageMetadataForPath:
- (NSDictionary*) imageMetadataForPath:(NSString*) imagePath{
NSURL *imageURL = [NSURL fileURLWithPath:imagePath];
CGImageSourceRef mySourceRef = CGImageSourceCreateWithURL((__bridge CFURLRef)imageURL, NULL);
NSDictionary * dict = (NSDictionary *) CFBridgingRelease(CGImageSourceCopyPropertiesAtIndex(mySourceRef,0,NULL));
CFRelease(mySourceRef);
return dict;
}
This is a copy and paste from a project of mine, you probably need to do a huge refactoring, also because it is using manual memory management in core foundation and you are using SWIFT. Of course by using this last set of instructions, the backend code must be prepared to deal with image orientation too.
If you want to know more about rotation, here is a link.
In my project i need to show the different sizes of images in zig-zag fashion. so, i converted the uiimages(url) which are coming from service to NSData and then i get the uiimage. my code is
NSURL *url = [NSURL URLWithString:[[_result objectAtIndex:i ] valueForKey:#"PImage"]];
NSData *data = [NSData dataWithContentsOfURL:url];
UIImage *image = [UIImage imageWithData:data];
so i can get the image size(width and height), But my problem is according to the image size, i need to create UIView, this code is works fine for me, but it is taking too much of time(almost 25 sec) to load 8 images. i figured converting UIImage to NSData is taking time. Is there any way to get the image size(width and height) without converting it into NSData
Thanks for spending time for me.
You can get image properties without actually loading whole image data from disk using ImageIO framework:
#import ImageIO;
...
NSURL *imageURL = … // Init URL somehow
CGImageSourceRef imgSource = CGImageSourceCreateWithURL((__bridge CFURLRef)url, NULL);
NSDictionary* imageProps = (__bridge_transfer NSDictionary*) CGImageSourceCopyPropertiesAtIndex(imgSource, 0, NULL);
NSLog(#"%#", imageProps);
CFRelease(imgSource);
Image width and height will be stored in dictionary under PixelHeight and PixelWidth keys (tested with png image, may be other image formats will use different keys)
Instead of converting url to data and to UIImage, Use EGOImageView OR AsyncImageView. You can simply pass the URL to them. Again setFrame based on size of the image.
my App requirement is to view uploaded documents from IPAD.
i am importing document from database in the form of BLOB image and passing it to IPAD and with below code i could view image.
NSString *strImage; // String has BLOB image from DB
NSData *imageData = [self dataFromBase64EncodedString:strImage];
UIImage *image = [UIImage imageWithData:imageData];
UIImageView *m_oImageViewer = [[UIImageView alloc]init];
m_oImageViewer.image = image;
m_oImageViewer.frame=CGRectMake((self.view.frame.size.width/2)- 250,60,500,500);
[self.view addSubview:m_oImageViewer];
-(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;
If PDF file converted to BLOB why i am getting image as nil, as i can see BLOB is common so why only .png files i can se and not PDF file even after converting to BLOB.
i read support document for UIImage it does not give PDF file but i am giving BLOB image. where i am going wrong.
i have to use any other property, or this is not possible.
PDF isn't image format, its something like container with text, fonts, vector and raster images etc, so you can't convert it into UIImage, but UIWebView can show pdf (and a lot another format). I think, you should save pdf BLOB to temp folder and then show it in UIWebView, something like:
[pdfData writeToFile:tempFilePath atomically:YES];
NSURL *url = [NSURL fileURLWithPath:tempFilePath];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
[self.webView loadRequest:request];
I had a lot of trouble trying to force the loading of the low-resolution version of some resources on iOS, when the high-res version (#2x) is also present.
The reason I wanted to do this is simple: My app shows a bunch of full-screen images to the user (320x480 on older devices, 640x960 on Retina devices), and the user can upload some of these to TwitPic. I wanted to unify the uploaded images to 320x480, regardless of the device (for consistency, because that size is fine in a web browser).
I found out that no matter what UIImage method I used, when the high-resolution version of a resource file is present it is loaded (even if you pass the full file path): UIImage will out-smart you. But I found a way to out-smart UIImage:
- (UIImage*) lowResImage{
NSString* path = [[NSBundle mainBundle] pathForResource:_fileName
ofType:#"png"
inDirectory:_resourceSubdirectory];
path = [path stringByReplacingOccurrencesOfString:#"##2x" withString:#""];
NSData* imageData = [[NSData alloc] initWithContentsOfFile:path];
UIImage* image = [[UIImage alloc] initWithData:imageData];
[imageData release];
return [image autorelease];
}
The above code works fine on a 4th generation iPod touch.
Anybody came up with a better approach?
Build your path, open data, and then init the image using data as in the example below.
NSString *dataPath = [[[NSBundle mainBundle] bundlePath] stringByAppendingPathComponent:_fileName];
NSData *data = [[NSData alloc] initWithContentsOfFile:dataPath];
UIImage *image3 = [UIImage imageWithData:data];