Q: I’m using iOS. How do I create a UIImage using PDFDraw without writing to disk?
A: The following code snippet shows how to use PDFDraw to create a UIImage of the first page of a PDFDoc:
PDFDoc* doc = [[PDFDoc alloc] initWithFilepath:file];
Page* page = [doc GetPage:1];
PDFDraw* draw = [[PDFDraw alloc] initWithDpi:dpi];
BitmapInfo* bitmapInfoObject;
@try
{
bitmapInfoObject = [draw GetBitmap:page pix_fmt:e_bgra demult:NO];
}
@catch (NSException* ex)
{
NSLog(@“PDFNet could not render.”);
}
NSData* data = [bitmapInfoObject GetBuffer];
unsigned char* test = calloc(sizeof(unsigned char)[bitmapInfoObject getWidth][bitmapInfoObject getHeight], sizeof(unsigned char));
[data getBytes:test length:sizeof(unsigned char)[bitmapInfoObject getWidth][bitmapInfoObject getHeight]];
UIImage* testImage = imageFromRawBGRAData(data, [bitmapInfoObject getWidth], [bitmapInfoObject getHeight], YES);
Where the method imageFromRawBGRAData is:
UIImage* imageFromRawBGRAData(NSData* data, int width, int height, bool retinaEnabled)
{
CGDataProviderRef provider = CGDataProviderCreateWithCFData((__bridge CFDataRef)data);
const int bitsPerComponent = 8;
const int bitsPerPixel = 4 * bitsPerComponent;
const int bytesPerRow = 4 * width;
CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB();
CGBitmapInfo bitmapInfo = kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Little;
CGColorRenderingIntent renderingIntent = kCGRenderingIntentDefault;
CGImageRef imageRef = CGImageCreate(width, height, bitsPerComponent, bitsPerPixel, bytesPerRow, colorSpaceRef, bitmapInfo, provider, NULL, NO, renderingIntent);
CGDataProviderRelease(provider);
double screenScale = 1;
if (retinaEnabled && [[UIScreen mainScreen] respondsToSelector:@selector(scale)] == YES)
screenScale = [[UIScreen mainScreen] scale] ;
UIImage *myImage = [UIImage imageWithCGImage:imageRef scale:screenScale orientation:UIImageOrientationUp];
CGImageRelease(imageRef);
CGColorSpaceRelease(colorSpaceRef);
return myImage;
}