CIColorMap過濾錯誤

Question

試圖用CIColorMap過濾器，但得到運行時錯誤「[NSImage中_feImage]：無法識別的選擇發送到實例0x100163b10」應用濾鏡

當在調試之後，我看到了RTE發生在applyColorMap的最後一行（返回）被執行。我知道兩個（JPG）文件存在（imageIn和在函數內初始化的文件）。所以...任何想法，爲什麼我得到這個錯誤？

CIColorMap的文檔說：inputGradientImage =屬性類型爲CIAttributeTypeGradient並且其顯示名稱爲Gradient Image的CIImage類。是我的問題，因爲我沒有確定「屬性類型」？我會怎麼做？

我的代碼是這樣的...在主線：

CIImage *myResult = [self applyColorMap: inputCIimage]; 

然後被調用的函數是：

- (CIImage*) applyColorMap: (CIImage*)imageIn { 
    // Convert imageIn to B&W by using a gradient image half white/half black 
    NSString *gradientFP = [[NSString alloc] initWithString:[self myFilepath: 
                 [NSString stringWithString:@"WB-1x20.jpg"]]]; 
    NSImage *colormapImage = [[NSImage alloc] initWithContentsOfFile:gradientFP]; 
    if (colormapImage == nil) { 
     NSLog (@"Bailing out. Gradient image allocation was NOT successful."); 
     return nil; 
    } 
    CIFilter *colorMapFilter = [CIFilter filterWithName:@"CIColorMap"]; 
    //[colorMapFilter setDefaults]; 
    [colorMapFilter setValue:imageIn forKey:@"inputImage"]; 
    [colorMapFilter setValue:colormapImage forKey:@"inputGradientImage"]; 
    return [colorMapFilter valueForKey:@"outputImage"]; //apply filter and return the new image 
} 

Answer 1

colormapImage需要是CIImage而不是NSImage，IIRC 。