April 22nd, 2011
A reader asked a me about image to PDF conversion a few days ago and I promised him an article, so here it is.
Image to PDF conversion is based on Quartz API. Using Quartz we can create PDF files and add content to them, the conversion actually means drawing the image on a PDF page.
March 28th, 2011
A common requirement when working with PDF files is to convert them to images. Because the iOS includes native PDF support, converting a PDF page to image seems easy. A graphic context is created for the image, the PDF page is rendered on image's graphic context and then the image is saved. Yet there is a catch when rendering the PDF page on the image's graphic context.
Now lets see how we put this idea into practice and convert a PDF page to image at a specific resolution.
March 23rd, 2011
Displaying a PDF page in an iPhone/iPad application seems pretty simple since the iOS includes a PDF API but there a few pitfalls. The iOS SDK includes the ZoomingPDFViewer sample and there are also several examples on the internet that show how to do this. The thing with Apple’s ZoomingPDFViewer and the other examples is that they have several flaws: rotated pages are not handled correctly, the actual position of MediaBox and CropBox is not considered, they cannot scale higher than 100% and they do not clip the content relative to CropBox as any PDF viewer does. The test files available for download at the end of this article let you verify these issues.
This article will show how to take care of the above problems and display a PDF page at a specific position in the view with a user defined zoom level.