CGContextDrawPDFPage taking up large amounts of memory

Question

I have a PDF file that I want to draw in outline form. I want to draw the first several pages on the document each in their own UIImage to use on a button so that when clic

Answer 1

Take a look at my code for a PDF image slicer on github:

http://github.com/luciuskwok/Maps-Slicer

There should be enough memory on the device that a 13 MB allocation isn't going to kill the app. Are you draining the autorelease pool each time you render a PDF? You might also want to cache the rendering into a UIImage so that it doesn't have to render it every time it's displayed.

Answer 2

Try to add :

CGContextSetInterpolationQuality(g, kCGInterpolationHigh);
CGContextSetRenderingIntent(g, kCGRenderingIntentDefault); 

before :

CGContextDrawPDFPage(g, m_page);

I had a similar issue and adding the 2 function call above resulted in the rendering using 5x less memory. Might be a bug in the CGContextXXX drawing functions