CODEWITHSUNDEEP
ioscore-image
HusseinB
HusseinB

Reputation: 1341

Applying filters in Core Image performance issues

My app applies filters to a picture after it has been selected/captured using Core Image. It works fine on small picture however if i take pictures by camera it takes about 3-4 seconds in order to process the picture and apply the filter. I read through the Core Image Programming Guide performance topics and i came across being able to decide if i want to use the CPU or GPU. So i applied what is written and it's still slow plus an error occurring in the console. I'll post the original code, the changes i applied to switch to GPU, and the error occurring.

Original code:

CIContext *context = [CIContext contextWithEAGLContext:nil]; //[CIContext contextWithOptions:@{kCIContextUseSoftwareRenderer: [NSNumber numberWithBool:NO]}];
    CIImage *image = [CIImage imageWithData:UIImagePNGRepresentation(_originalImage)];
    CIFilter *filter = [CIFilter filterWithName:_filters[filterName]];
    if ([filterName isEqualToString:@"Sepia"]) {
        [filter setValue:image forKey:kCIInputImageKey];
        [filter setValue:@0.8f forKey:kCIInputIntensityKey];
    }
    if ([filterName isEqualToString:@"B/W"]) {
        [filter setValue:image forKey:kCIInputImageKey];
    }
    if ([filterName isEqualToString:@"Bloom"]) {
        [filter setValue:image forKey:kCIInputImageKey];
        [filter setValue:@1.0f forKey:kCIInputRadiusKey];
        [filter setValue:@1.0f forKey:kCIInputIntensityKey];
    }
    CIImage *result = [filter valueForKey:kCIOutputImageKey];
    CGRect extent = [result extent];
    CGImageRef cgimage = [context createCGImage:result fromRect:extent];
    UIImage *filteredImage = [UIImage imageWithCGImage:cgimage];
    [_filteredImageView setImage:filteredImage];
    tempFilteredImage = filteredImage;

Modified code for the context:

CIContext *context = [CIContext contextWithEAGLContext:nil];

Error occurring after changing the CIContext code:

CIContexts can only be created with ES 2.0 EAGLContexts

Is there something wrong in code ? am i doing the right thing to accelerate the process of rendering ? Thank you.

Upvotes: 0

Views: 1291

Answers (1)

maelswarm
maelswarm

Reputation: 1070

Try making the context like this...

EAGLContext *myEAGLContext = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2];
CIContext *myContext = [CIContext contextWithEAGLContext:myEAGLContext options:nil];

Upvotes: 1

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