#include <ApplicationServices/ApplicationServices.h>

int main(int argc, const char *argv[])
{
    if (argc != 3)
    {
        printf("usage: imageconvert <infile> <outfile>\n");
        exit(EXIT_FAILURE);
    }
    
    const char *in_path = argv[1];
    const char *out_path = argv[2];
    
    CFStringRef in_path_string = CFStringCreateWithCString(
        kCFAllocatorDefault,
        in_path,
        kCFStringEncodingUTF8);
    CFURLRef in_path_url = CFURLCreateWithFileSystemPath(
        kCFAllocatorDefault,
        in_path_string,
        kCFURLPOSIXPathStyle,
        FALSE);
    
    CGImageSourceRef image_source = CGImageSourceCreateWithURL(
        in_path_url,
        NULL);
    
    CGImageRef image = CGImageSourceCreateImageAtIndex(
        image_source, 
        0,
        NULL);

    CFStringRef out_path_string = CFStringCreateWithCString(
        kCFAllocatorDefault,
        out_path,
        kCFStringEncodingUTF8);
    CFURLRef out_path_url = CFURLCreateWithFileSystemPath(
        kCFAllocatorDefault,
        out_path_string,
        kCFURLPOSIXPathStyle,
        FALSE);
    
    CFStringRef out_extension = CFStringCreateWithCString(
        kCFAllocatorDefault,
        strrchr(out_path, '.') + 1,
        kCFStringEncodingUTF8);
    
    CFStringRef out_type = UTTypeCreatePreferredIdentifierForTag(
        kUTTagClassFilenameExtension,
        out_extension,
        NULL);
    
    CGImageDestinationRef image_destination = CGImageDestinationCreateWithURL(
        out_path_url,
        out_type,
        1,
        NULL);
    
    CGImageDestinationAddImage(
        image_destination,
        image,
        NULL);
    
    CGImageDestinationFinalize(image_destination);
    
    CFRelease(image_destination);
    CFRelease(out_type);
    CFRelease(out_extension);
    CFRelease(out_path_url);
    CFRelease(out_path_string);
    CFRelease(image);
    CFRelease(image_source);
    CFRelease(in_path_url);
    CFRelease(in_path_string);
    
    return EXIT_SUCCESS;
}