使用GPUImage滤镜后无法保存图像

Question

Some of my code at follow:

GPUImagePicture*  staticPicture = [[GPUImagePicture alloc] initWithImage:[info objectForKey:UIImagePickerControllerOriginalImage] smoothlyScaleOutput:YES];

GPUImageSaturationFilter * filter = [[GPUImageSaturationFilter alloc] init];
[filter setSaturation:0.2];
[filter addTarget:((GPUImageView *)gpuImageView)];

[staticPicture addTarget:filter];
[staticPicture processImage];

_saveImage = [filter imageFromCurrentFramebuffer];

[self.testImageView setImage:_saveImage];

I want use imageFromCurrentFramebuffer to get the image with filter, but i get always nil.Use [self.testImageView setImage:_saveImage] always get blank.

Do i get the image in a wrong way?Any sugesst is welcome. A lot of thanks.

Answer 1

You need to call

[filter useNextFrameForImageCapture];

on a line right before you call

[staticPicture processImage];

Otherwise, the filter won't know to hang on to its processed framebuffer long enough for you to capture your image.