cocoa touch - How do I draw into a bitmap without antialiasing/interpolation in iOS? -


i'm trying programmatically draw uiimage so:

- (void)viewdidload {     [super viewdidload];     // additional setup after loading view, typically nib.      uigraphicsbeginimagecontextwithoptions(cgsizemake(2, 2), yes, 1);      cgcontextref context = uigraphicsgetcurrentcontext();      // these 3 lines of code apparently nothing.     cgcontextsetinterpolationquality(context, kcginterpolationnone);     cgcontextsetallowsantialiasing(context, false);     cgcontextsetshouldantialias(context, false);      cgcontextsetfillcolorwithcolor(context, [uicolor colorwithred:1 green:0 blue:0 alpha:1].cgcolor);     cgcontextfillrect(context, cgrectmake(0, 0, 1, 1));      self.imageview.image = uigraphicsgetimagefromcurrentimagecontext();      uigraphicsendimagecontext(); }

this code works except resulting image soft, aggressive attempt @ antialiasing/interpolation. need image scaled using nearest neighbour interpolation. how prevent antialiasing?

thank you!

while image draw context doesn't use anti-aliasing (even though doesn't make difference particular image you're drawing), still default interpolation behavior image view.

to change that, adjust magnificationfilter/minificationfilter properties of view's layer:

self.imageview.layer.magnificationfilter = kcafilternearest; self.imageview.layer.minificationfilter = kcafilternearest;

(you need add quartzcore framework work.)


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