gistfile1.m

if(scrollView.tag == 200) {
        int page = floor(scrollView.contentOffset.x / kSlideImageWidth);
        float hRatio = (scrollView.contentOffset.x - kSlideImageWidth * page) / kSlideImageWidth;
        
        if(page == [placeImageList count]-1) return;
        
        NSDictionary *currentImageInfo = [placeImageList objectAtIndex:page];
        NSDictionary *nextImageInfo = [placeImageList objectAtIndex:page+1];
        
        float currentHeight = [[currentImageInfo objectForKey:@"height"] floatValue] / [[currentImageInfo objectForKey:@"width"] floatValue] * kSlideImageWidth;
        float nextHeight = [[nextImageInfo objectForKey:@"height"] floatValue] / [[nextImageInfo objectForKey:@"width"] floatValue] * kSlideImageWidth;
        
        float newHeight = currentHeight + (nextHeight - currentHeight) * hRatio;
        [scrollView setFrame:CGRectMake(0, 0, kSlideImageWidth, newHeight)];
        
        [detailView setFrame:CGRectMake(0, newHeight + 10, detailView.width, detailView.height)];
    }