IOS coreimage/image Blur (i)

Coreimage is introduced from iOS5.0, and its powerful not by Marvel.

Whether it is sweep, generate two-dimensional code, face recognition, image compression, filters and other processing, should have.

image Blur is supported from 6.0 onwards, we look at a simple example below.

First, an object is introduced: Ciimage is not UIImage.

Ciimage is a picture object in the Coreimage.

The common way to create is

<span style= "FONT-SIZE:14PX;" >+ (Ciimage *) Imagewithcontentsofurl: (Nsurl *) url;+ (Ciimage *) Imagewithcontentsofurl: (nsurl *) URL options: ( Nsdictionary *) d;+ (Ciimage *) Imagewithdata: (NSData *) data;+ (Ciimage *) Imagewithdata: (NSData *) Data options: ( Nsdictionary *) d;</span>

We can create a Ciimage object first

1. First you import 1. JPG files into the project. Then introduce the resource path

<span style= "FONT-SIZE:14PX;" >    ciimage *beginimage = [ciimage imagewithcontentsofurl:[[nsbundle mainbundle] urlforresource:@ "1.jpg" Withextension:nil]];</span>

2. Create a Cicontext context

<span style= "FONT-SIZE:14PX;" >    Cicontext *context = [Cicontext contextwithoptions:nil];</span>

3. Create a filter

Cifilter is a filter object that needs to pass in a filter name. (There are nearly hundreds of filter names). Kciinputimagekey refers to the key of the input image

Cifilter *filter = [Cifilter filterwithname:@ "Cigaussianblur" keysandvalues:kciinputimagekey,beginimage, nil];

4. Get the picture of the output

<span style= "FONT-SIZE:14PX;" >    Ciimage *outputimage = [Filter outputimage];</span>

5. Create a piece of cgimageref by context

<span style= "FONT-SIZE:14PX;" >cgimageref ref = [Context Createcgimage:outputimage fromrect:[outputimage extent]];</span>

6. Convert ref to UIImage object

<span style= "FONT-SIZE:14PX;" >    UIImage *newimage = [UIImage imagewithcgimage:ref];</span>

7. Freeing up memory

<span style= "FONT-SIZE:14PX;" >cgimagerelease (ref);</span>

If you create more cicontext, you will consume memory very much.

So, in general I recommend that you refer to the Cicontext\cifiter object as a property.

That's all you can do.

Suppose we need to have a slider to set the blur amount of the picture.

----slide to change the transparency of the picture

Slider To change the transparency when changing value

<span style= "FONT-SIZE:14PX;" >[self.slider addtarget:self Action: @selector (Sliderchangevalue:) forcontrolevents:uicontroleventvaluechanged] ;</span>

<span style= "FONT-SIZE:14PX;" >-(void) Sliderchangevalue: (UISlider *) slider{        [Self.filter setValue:self.beginImage Forkeypath: Kciinputimagekey];    [Self.filter setvalue:[nsnumber NumberWithFloat:slider.value *] forkey:@ "Inputradius"];        Get filtered picture    ciimage *outputimage = [Self.filter outputimage];        Convert picture    cgimageref cgimg = [Self.context createcgimage:outputimage fromrect:[outputimage extent];    UIImage *newimg = [UIImage imagewithcgimage:cgimg];    Show Image    [Self.imagev setimage:newimg];    Release C object    cgimagerelease (cgimg);} </span>

That's all you can do.

IOS coreimage/image Blur (i)