colorAt does not return the proper color

[ggrigorov]

Hi All, I am using a white rectangle (10 by 10 pixels) and I am trying (unsuccessfully) to read the color and bring it back as a value

so, this is my code:

local img = hs.image.imageFromPath("test-white.png") local col = img:colorAt({2,2}) print(hs.inspect(col))

Since the entire image is a solid white color #FFFFFF I am expecting to see is expected result{ alpha = 1.0, blue = 1.0, green = 1.0, red = 1.0 }

Instead, I have this observed result{ __luaSkinType = "NSColor", alpha = 1.0, blue = 0.99984186887741, green = 1.0, red = 0.99989891052246 }

What am I doing wrong?

[latenitefilms]

Ummmm, good question. I can only assume it's either a maths/rounding issue (maybe you simply need to round up the value to one decimal place?), or something to do with ColorSync. @asmagill might have some ideas?

hs.image:colorAt() is fairly basic:

/// hs.image:colorAt(point) -> table
/// Method
/// Reads the color of the pixel at the specified location.
///
/// Parameters:
///  * `point` - a `hs.geometry.point`
///
/// Returns:
///  * A `hs.drawing.color` object
static int colorAt(lua_State* L) {
    LuaSkin *skin = [LuaSkin shared] ;
    [skin checkArgs:LS_TUSERDATA, USERDATA_TAG, LS_TTABLE, LS_TBREAK] ;

    // Source: https://stackoverflow.com/a/33485218/6925202
    @autoreleasepool {
    	NSImage *theImage = [skin luaObjectAtIndex:1 toClass:"NSImage"] ;
    	NSPoint point  = [skin tableToPointAtIndex:2] ;

		// Source: https://stackoverflow.com/a/48400410
		[theImage lockFocus];
		NSColor *pixelColor = NSReadPixel(point);
		[theImage unlockFocus];
        [skin pushNSObject:pixelColor];
	}

    return 1;
}

...however, looking at it now, it is using a deprecated method, so it might be worth looking into something like this.

[romeovs]

Has a solution aver been found for this? Can the StackOverflow answer be merged? I'm happy to provide a PR if that's the way forward.