pixelcolor.m

#import <Foundation/Foundation.h>
#import <AppKit/AppKit.h>

int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
    
	if (argc != 4) {
		printf("Usage: pixelcolor [imgpath] [pixelposx] [pixelposy]\n");
		return 1;
	}
	[NSApplication sharedApplication];
	NSArray *args = [[NSProcessInfo processInfo] arguments];
	NSString *filePath = [args objectAtIndex:1];
	NSString *stringPosX = [args objectAtIndex:2];
	float pixelPosX = [stringPosX floatValue];
	NSString *stringPosY = [args objectAtIndex:3];
	float pixelPosY = [stringPosY floatValue];
    NSImage *img = [[NSImage alloc] initWithContentsOfFile:filePath];
	if (img == nil) {
		printf("Error: Could not load image file.\n");
		return 1;
	}
    NSPoint point = NSMakePoint(pixelPosX, pixelPosY);
    [img lockFocus];
    NSColor *color = NSReadPixel(point);
    [img unlockFocus];
	[img release];
	float red, green, blue, alpha;
	[color getRed:&red green:&green blue:&blue alpha:&alpha];
	printf("%f %f %f %f\n", red, green, blue, alpha);
	
    [pool drain];
    return 0;
}