I have been using GPUImage for my project and I am getting into this problem where imageFromCurrentFramebuffer returns nil for some of the GPUImageLookupFilter's.
I subclassed GPUImageFilterGroup like in the GPUImageAmatorkaFilter my code is as follows:
-(MTLookupFilter *) initWithLookupImageName:(NSString *) lookupImageName { self = [super init]; if (self) { UIImage *image = [UIImage imageNamed:lookupImageName]; self.lookupImageSource = [[GPUImagePicture alloc] initWithImage:image]; GPUImageLookupFilter *lookupFilter = [[GPUImageLookupFilter alloc] init]; [self addFilter:lookupFilter]; [self.lookupImageSource addTarget:lookupFilter atTextureLocation:1]; [self.lookupImageSource processImage]; self.initialFilters = [NSArray arrayWithObjects:lookupFilter, nil]; self.terminalFilter = lookupFilter; } return self; } I have several of the objects of this class added into an array and I use:
- (IBAction)filterAction:(id)sender { NSInteger index = arc4random()%self.filtersArray.count; id filter = self.filtersArray[index]; GPUImagePicture *stillImageSource = [[GPUImagePicture alloc] initWithImage:self.fullImage]; UIImage *filteredimage = nil; [stillImageSource addTarget:filter]; [stillImageSource processImage]; [filter useNextFrameForImageCapture]; filteredimage = [filter imageFromCurrentFramebuffer]; if (filteredimage) { self.imageView.image = filteredimage; } else { NSLog(@"Filtered image is nil"); } } The returned image from imageFromCurrentFramebuffer is sometimes nil and I do not understand it's cause. I would be thankful for any help. Sometimes the image is nil even for the filters, GPUImageAmatorkaFilter, GPUImageSoftEleganceFilter and `GPUImageMissEtikateFilter so I know it is not a problem with my subclass.