IOS Add filters to pictures & use opengles dynamic rendering pictures and examples _ios

iOS add filters to pictures & use Opengles to dynamically render pictures

Add a filter to a picture in both ways: coreimage/opengles

here's how to add a filter to a picture using coreimage, mainly for the following steps:

#1. Import original pictures in ciimage format

#2. Create Cifilter Filter

#3. Render the picture in the filter with Cicontext

#4. Export a rendered picture

Reference code:

Import ciimage
  Ciimage *ciimage = [[Ciimage alloc] initwithimage:[uiimage imagenamed:@ "Hua"]];
  
  Create a filter filter
  cifilter *filter = [Cifilter filterwithname:@ "Cipixellate"];
  
  [Filter Setvalue:ciimage Forkey:kciinputimagekey];
  
  [Filter setdefaults];
  
  Ciimage *outimage = [Filter Valueforkey:kcioutputimagekey];
  
  Use Cicontext to render the picture in the filter
  cicontext *context = [Cicontext contextwithoptions:nil];
  
  Cgimageref cgimage = [Context createcgimage:outimage
                    fromrect:[outimage extent]];
  
  Export picture
  uiimage *showimage = [UIImage imagewithcgimage:cgimage];
  
  Cgimagerelease (cgimage);
  
  Uiimageview *imageview = [[Uiimageview alloc] initwithimage:showimage];
  Imageview.center    = self.view.center;
  [Self.view Addsubview:imageview];

When you want to set more than one filter, there is a new cifilter to create an additional kciinputanglekey, the code is as follows:

Import ciimage Ciimage *ciimage = [[Ciimage alloc] initwithimage:[uiimage imagenamed:@ "Hua.jpeg"]];
  
  Create a filter filter cifilter *filter = [Cifilter filterwithname:@ "Cipixellate"];
  
  [Filter Setvalue:ciimage Forkey:kciinputimagekey];
  
  [Filter SetDefaults];
  
  Ciimage *outimage = [Filter Valueforkey:kcioutputimagekey];
  
  Cifilter *filtertwo = [Cifilter filterwithname:@ "Cihueadjust"];
  
  [Filtertwo setvalue:outimage Forkey:kciinputimagekey];
  
  [Filtertwo SetDefaults]; [Filtertwo setvalue:@ (1.0f) Forkey:kciinputanglekey];
  
  If this line does not increase the new filter will not take effect ciimage *outputimage = [Filtertwo Valueforkey:kcioutputimagekey]; 
  
  Use Cicontext to render the picture in the filter cicontext *context = [Cicontext Contextwithoptions:nil];
  
  Cgimageref cgimage = [Context Createcgimage:outputimage fromrect:[outputimage extent]];
  
  Export picture UIImage *showimage = [UIImage imagewithcgimage:cgimage];
  
  Cgimagerelease (Cgimage); Uiimageview *imageview = [[Uiimageview alloc] InitwithImage:showimage];
  Imageview.center = Self.view.center; [Self.view Addsubview:imageview];

Here's how to use Opengles to render a picture with a filter

The steps to use Opengles are roughly as follows:

#1. Import the picture you want to render

#2. Get the context of opengles rendering

#3. Create a rendered Glkview buffer

#4. Create a Coreimage context

#5. Related Settings for Coreimage

#6. Start rendering and display pictures

The reference code is as follows:

Import the picture you want to render uiimage *showimage = [uiimage imagenamed:@ "Hua.jpeg"];
  
  CGRect rect = CGRectMake (0, 0, showImage.size.width, showImage.size.height);
  
  Gets the context Eaglcontext *eagcontext of the opengles rendering = [[Eaglcontext alloc] initwithapi:keaglrenderingapiopengles2];
  Creates a rendered buffer glkview *glkview = [[Glkview alloc] Initwithframe:rect Context:eagcontext];
  [Glkview binddrawable];
  
  [Self.view Addsubview:glkview]; Create a coreimage context cicontext *cicontext = [cicontext contextwitheaglcontext:eagcontext option
  
  S:@{kcicontextworkingcolorspace: [Nsnull NULL]}];
  
  Coreimage Related Settings Ciimage *ciimage = [[Ciimage alloc] initwithimage:showimage];
  
  Cifilter *filter = [Cifilter filterwithname:@ "Cisepiatone"];
  [Filter Setvalue:ciimage Forkey:kciinputimagekey];
  
  [Filter setvalue:@ (0) Forkey:kciinputintensitykey]; Start rendering [Cicontext Drawimage:[filter Valueforkey:kcioutputimagekey] Inrect:cgrectmake (0, 0, GLKVIEW.DRawablewidth, Glkview.drawableheight) fromrect:[ciimage extent]]; [Glkview display];

If you want dynamic rendering, you can dynamically adjust the Vaule value of the code through Uisilder

[Filter Setvalue:vaule Forkey:kciinputintensitykey];

Thank you for reading, I hope to help you, thank you for your support for this site!