⚠️ Warning: This is a draft ⚠️
This means it might contain formatting issues, incorrect code, conceptual problems, or other severe issues.
If you want to help to improve and eventually enable this page, please fork RosettaGit's repository and open a merge request on GitHub.
{{task|GUI}} [[Category:Testing]]
;Task: Get color information from an arbitrary pixel on the screen, such as the current location of the mouse cursor.
The mouse cursor may or may not have to be active in a GUI created by your program. These functions are OS related.
App Inventor
App Inventor has two Canvas blocks to determine the color under a pixel.
'''GetBackgroundPixelColor''' returns a color from the Canvas but ignores Ball sprites and ImageSprites.
'''GetPixelColor''' returns a color from either the Canvas or a Ball sprite or ImageSprite.
In the app's display below, the purple Ball sprite was touched on the left canvas, but the pixel color (green) returned was from the area below it.
[https://lh4.googleusercontent.com/-Gw0xm7RIEck/Uute2nQSGsI/AAAAAAAAJ90/rq3UuWYE9Yw/s1600/Capture.PNG
AutoHotkey
PixelGetColor, color, %X%, %Y%
AutoIt
Opt('MouseCoordMode',1) ; 1 = (default) absolute screen coordinates
$pos = MouseGetPos()
$c = PixelGetColor($pos[0], $pos[1])
ConsoleWrite("Color at x=" & $pos[0] & ",y=" & $pos[1] & _
" ==> " & $c & " = 0x" & Hex($c) & @CRLF)
{{Out}}
Color at x=3,y=733 ==> 3829413 = 0x003A6EA5
Axe
Disp pxl-Test(50,50)▶Dec,i
BaCon
BaCon can make use of the High Performance Canvas include. Outside this canvas it needs to access XLib API functions.
INCLUDE canvas
FULLSCREEN
color = GETINK(100, 100, 4)
WAITKEY
BASIC
=
Applesoft BASIC
= [http://en.wikipedia.org/wiki/Apple_II_graphics#Low-Resolution_.28Lo-Res.29_graphics Low-Resolution (Lo-Res) graphics] 40x48, 16 colors, page 1
X = PDL (0) * 5 / 32
Y = PDL (1) * 3 / 16
COLOR= SCRN( X,Y)
[http://en.wikipedia.org/wiki/Apple_II_graphics#High-Resolution_.28Hi-Res.29_graphics Hi-Resolution (Hi-Res) graphics] 280x192, 6 colors
There is no HSCRN( X,Y) function in Applesoft. What follows is an elaborate subroutine that determines the hi-res color at the location given by variables X and Y on the current hi-res page. A color value in the range from 0 to 7 is returned in the variable C. The color is determined by peeking at adjacent pixels and the Most Significant Bit [http://en.wikipedia.org/wiki/Most_significant_bit MSB]. The VTAB routine is used as an aid to calculate the address of pixels. Other colors beyond the 6 hi-res colors can be displayed by positioning pixels at byte boundaries using the MSB. This routine is limited to the eight hi-res colors.
100 REM GET HCOLOR
110 REM PARAMETERS: X Y
120 REM RETURNS: C
130 REM
140 P = 0:X = X + 1
150 ON (X < 280) GOSUB 300
160 PR = P:P = 0:X = X - 2
170 ON (X > = 0) GOSUB 300
180 PL = P:X = X + 1: GOSUB 300
190 ODD = X - INT (X / 2) * 2
200 C = H * 4
210 IF NOT ((PL = PR) AND (PL < > P)) THEN C = C + P * 3: RETURN
220 IF ODD THEN P = NOT P
230 C = C + P + 1
240 RETURN
250 REM
260 REM GET PIXEL
270 REM PARAMETERS: X Y
280 REM RETURNS: H P
290 REM
300 H = INT (X / 7)
310 V = INT (Y / 8)
320 VO = PEEK (37)
330 HO = PEEK (36)
340 VTAB V + 1: HTAB 1
350 A = PEEK (41) * 256
360 A = A + PEEK (40) + H
370 VTAB VO + 1: HTAB HO + 1
380 A = A + 8192 - 1024
390 P = PEEK (230) / 32
400 IF P = 2 THEN A = A + 8192
410 A = A + (Y - V * 8) * 1024
420 B = X - H * 7
430 V = PEEK (A)
440 H = INT (V / 128)
450 V = INT (V / (2 ^ B))
460 P = V - INT (V / 2) * 2
470 RETURN
X = 267 : Y = 166 : GOSUB 100
HCOLOR= C
=
BBC BASIC
= In [[BBC BASIC for Windows]] you can read either the 'logical colour' (palette index) or the 'true colour' (24-bit RGB value).
palette_index% = POINT(x%, y%)
RGB24b_colour% = TINT(x%, y%)
=
Commodore BASIC
=
'''Example 1:''' Commodore 64
There are no graphics commands in Commodore 64 BASIC. High resolution (hires) graphics are programmed by directly manipulating the hardware registers and memory.
The Commodore 64 hires bitmap is 320×200, subdivided into 8×8 cells starting at the top left and moving right. Each cell is addressed top to bottom by 8 bytes. Each byte controls a horizontal row of 8 bits. This requires calculation on the programmer's part to translate X,Y coordinates into a specific memory address/value combination (lines 1210 through 1220).
5 rem commodore 64 example
10 base=2*4096:x=100:y=50:poke53280,0
20 gosub 1000:print chr$(147);
30 bg=11:fg=1:rem set foreground and background colors
40 for i=1024 to 1503:poke i,fg*16+bg:next
50 for i=base to base+7990:poke i,0:next
60 gosub 1200
70 poke byte, peek(byte) or 2^bit
80 print"{home}{crsr-down 14}";
90 px=((peek(byte) and 2^bit)>0)
100 co=peek(cb)and(15+(-225*px)):if px then co=co/16
110 print"pixel color at";x;"{crsr-left},";y;"{crsr-left}:";co;"{crsr-left} "
120 getk$:ifk$=""then 120
130 gosub 1100:end
1000 rem turn on graphics
1010 poke53272,peek(53272) or 8
1020 poke53265,peek(53265) or 32
1030 return
1100 rem turn off graphics
1110 poke53265,peek(53265) and 223
1120 poke53272,peek(53272) and 247
1130 return
1200 rem convert x-y into mem location
1210 ro=int(y/8):ch=int(x/8):li=y and 7
1220 bit=7-(x and 7):byte=base+ro*320+char*8+li:cb=1024+ro+ch
1230 return
'''Example 2:''' Commodore Plus 4 and 128
On both machines, there is a split graphics-text screen that can be used, and the extended BASIC provides functions for reading pixel and color values from the bitmap.
10 color 0,1:color 1,3: rem set border to black and pixel color to red
15 graphic 2,1: rem enter split graphics/text mode and clear screen
20 draw 1,100,50 : rem plot pixel at 100,50
30 print "pixel color at";rdot(0);",";rdot(1);"is";rclr(rdot(2))
40 get k$:if k$="" then 40
50 graphic 0,1 : rem return to text mode
=
FreeBASIC
= This is a very simple example from the FreeBASIC documentation. To obtain the color of an arbitrary screen pixel (i.e. outside the graphics screen controlled by FB) one would need to use API functions.
FB 1.05.0 Win64
' Set an appropriate screen mode - 320 x 240 x 8bpp indexed color
ScreenRes 320, 240, 8
' Draw a line using color 12 (light red)
Line (20,20)-(100,100), 12
' Print the color of a point on the line
Print Point(20,20) '' prints 12
' Sleep before the program closes
Sleep
=
QuickBASIC
= {{works with|QuickBasic|4.5}}
In a graphics mode (for instance, SCREEN 13 or SCREEN 12)
color = point(x, y)
=
Integer BASIC
=
See [[#Applesoft BASIC|Applesoft BASIC]].
=
Liberty BASIC
=
'This example requires the Windows API
Struct point, x As long, y As long
hDC = GetDC(0)
result = GetCursorPos()
Print GetPixel(hDC, point.x.struct, point.y.struct)
Call ReleaseDC 0, hDC
End
Sub ReleaseDC hWnd, hDC
CallDLL #user32,"ReleaseDC", hWnd As uLong, hDC As uLong, ret As Long
End Sub
Function GetDC(hWnd)
CallDLL #user32, "GetDC", hWnd As uLong, GetDC As uLong
End Function
Function GetCursorPos()
CallDLL #user32, "GetCursorPos", point As struct, GetCursorPos As uLong
End Function
Function GetPixel(hDC, x, y)
CallDLL #gdi32, "GetPixel", hDC As uLong, x As long, y As long, GetPixel As long
End Function
=
Locomotive Basic
=
10 x=320:y=200
20 color=TEST(x,y)
30 PRINT "Pen color at"; x; y; "is"; color
=
PureBasic
= Return the color used at the x,y position in the current output. If the current output has an alpha channel then the result will be a 32bit RGBA value, otherwise it will be a 24bit RGB value. The color can be split in their RGB and alpha values by using the Red(), Green(), Blue() and Alpha() functions.
Color = Point(x, y)
To get the colour of a pixel on the screen when it is not managed by PureBasic (ie. from other programs' windows), it is necessary to use Windows API. This works only under Windows.
hDC = GetDC_(0)
Color = GetPixel_(hDC, x, y)
ReleaseDC_(0, hDC)
This work fine!!
poz.point
If OpenWindow(0,0,0,100,45,"Get pixel color at cursor position",#PB_Window_MinimizeGadget)
TextGadget(0,0,0,50,12,"Red: ")
TextGadget(1,0,15,50,12,"Green: ")
TextGadget(2,0,30,50,12,"Blue: ")
TextGadget(3,50,0,50,12,"")
TextGadget(4,50,15,50,12,"")
TextGadget(5,50,30,50,12,"")
hDC = GetDC_(0)
Repeat
oldx=poz\x
oldy=poz\y
GetCursorPos_(@poz)
Color = GetPixel_(hDC, poz\x, poz\y)
If poz\x<>oldx Or poz\y<>oldy
SetGadgetText(3,Str(Red(color)))
SetGadgetText(4,Str(Green(color)))
SetGadgetText(5,Str(Blue(color)))
EndIf
event=WaitWindowEvent(200)
Until event=#PB_Event_CloseWindow
ReleaseDC_(0, hDC)
EndIf
=
SmileBASIC
=
DEF GETPX X,Y OUT R,G,B
PCOL=GSPOIT(X,Y)
RGBREAD PCOL OUT R,G,B
END
==={{header|TI-89 BASIC}}=== Only the graph screen can be read.
pxlTest(y, x) © returns boolean
=
Visual Basic .NET
=
Private Function GetPixelColor(ByVal Location As Point) As Color
Dim b As New Bitmap(1, 1)
Dim g As Graphics = Graphics.FromImage(b)
g.CopyFromScreen(Location, Point.Empty, New Size(1, 1))
Return b.GetPixel(0, 0)
End Function
=
VBA
= In "pure" Visual Basic for Application, there is no way to find the color of a screen pixel. We have to use api's functions. This code should be adapted for 64 bits versions...
Option Explicit
Private Type POINTAPI
x As Long
y As Long
End Type
Private Declare Function GetPixel Lib "gdi32" (ByVal hdc As Long, ByVal x As Long, ByVal y As Long) As Long
Private Declare Function GetCursorPos Lib "USER32" (lpPoint As POINTAPI) As Long
Private Declare Function GetWindowDC Lib "USER32" (ByVal hWnd As Long) As Long
Sub Color_of_a_screen_pixel()
Dim myColor As Long
myColor = Get_Color_Under_Cursor
End Sub
Function Get_Color_Under_Cursor() As Long
Dim Pos As POINTAPI, lngDc As Long
lngDc = GetWindowDC(0)
GetCursorPos Pos
Get_Color_Under_Cursor = GetPixel(lngDc, Pos.x, Pos.y)
End Function
=
Yabasic
=
open window 100, 100
backcolor 255, 0, 0
clear window
color 0, 255, 0
fill rectangle 50, 50, 75, 75
x = 60 : y = 60
s$ = right$(getbit$(x, y, x, y), 6)
blue = dec(right$(s$, 2))
green = dec(mid$(s$, 3, 2))
red = dec(left$(s$, 2))
print red, " ", green, " ", blue
=
ZX Spectrum Basic
=
The built-in function POINT (x,y) returns 0 if the pixel at x,y is set to the relevant PAPER colour, or 1 if it is set to the INK colour. (Note that there can only be a maximum of two colours in each 8x8-pixel section of the screen.)
C
{{libheader|Xlib}}
#include <X11/Xlib.h> void get_pixel_color (Display *d, int x, int y, XColor *color) { XImage *image; image = XGetImage (d, RootWindow (d, DefaultScreen (d)), x, y, 1, 1, AllPlanes, XYPixmap); color->pixel = XGetPixel (image, 0, 0); XFree (image); XQueryColor (d, DefaultColormap(d, DefaultScreen (d)), color); } // Your code XColor c; get_pixel_color (display, 30, 40, &c); printf ("%d %d %d\n", c.red, c.green, c.blue);
{{works with|Windows}} (Linux users, see [http://www.muquit.com/muquit/software/grabc/grabc.html grabc].)
#include <Windows.h> COLORREF getColorAtCursor(void) { POINT p; COLORREF color; HDC hDC; BOOL b; /* Get the device context for the screen */ hDC = GetDC(NULL); if (hDC == NULL) return CLR_INVALID; /* Get the current cursor position */ b = GetCursorPos(&p); if (!b) return CLR_INVALID; /* Retrieve the color at that position */ color = GetPixel(hDC, p.x, p.y); /* Release the device context again */ ReleaseDC(GetDesktopWindow(), hDC); return color; }
C++/CLI
using namespace System; using namespace System::Drawing; using namespace System::Windows::Forms; [STAThreadAttribute] int main() { Point^ MousePoint = gcnew Point(); Control^ TempControl = gcnew Control(); MousePoint = TempControl->MousePosition; Bitmap^ TempBitmap = gcnew Bitmap(1,1); Graphics^ g = Graphics::FromImage(TempBitmap); g->CopyFromScreen((Point)MousePoint, Point(0, 0), Size(1, 1)); Color color = TempBitmap->GetPixel(0,0); Console::WriteLine("R: "+color.R.ToString()); Console::WriteLine("G: "+color.G.ToString()); Console::WriteLine("B: "+color.B.ToString()); }
C#
using System; using System.Drawing; using System.Windows.Forms; class Program { static Color GetPixel(Point position) { using (var bitmap = new Bitmap(1, 1)) { using (var graphics = Graphics.FromImage(bitmap)) { graphics.CopyFromScreen(position, new Point(0, 0), new Size(1, 1)); } return bitmap.GetPixel(0, 0); } } static void Main() { Console.WriteLine(GetPixel(Cursor.Position)); } }
Sample output:
## Clojure
```lisp
(defn get-color-at [x y]
(.getPixelColor (java.awt.Robot.) x y))
Common Lisp
Using Allegro and their Common Graphics package
(in-package :cg-user) (defun print-hex (n) (let ((*print-base* 16.) (*print-radix* t)) (print n)) t) (defun get-byte (n byte) (logand (ash n (* byte -8)) #xFF)) (defun get-pixel (x y) (let ((pixval (caar (contents (get-screen-pixmap :box (make-box x y (+ x 1) (+ y 1))))))) (mapcar #'(lambda (i) (get-byte pixval i)) '(2 1 0 3)))) (defun get-mouse-pixel () (let ((pos (cursor-position (screen *system*)))) (get-pixel (position-x pos) (position-y pos)))) (print-hex (get-mouse-pixel))
Sample output: (values are in RGBA order):
(#xe0 #x43 #x43 #xff)
Delphi
program ScreenPixel;
{$APPTYPE CONSOLE}
uses
Windows,
SysUtils,
Graphics;
// Use this function in a GUI application to return the color
function GetPixelColourAsColor(const PixelCoords: TPoint): TColor;
var
dc: HDC;
begin
// Get Device Context of windows desktop
dc := GetDC(0);
// Read the color of the pixel at the given coordinates
Result := GetPixel(dc,PixelCoords.X,PixelCoords.Y);
end;
// Use this function to get a string representation of the current colour
function GetPixelColourAsString(const PixelCoords: TPoint): string;
var
r,g,b: Byte;
col: TColor;
begin
col := GetPixelColourAsColor(PixelCoords);
// Convert the Delphi TColor value to it's RGB components
r := col and $FF;
g := (col shr 8) and $FF;
b := (col shr 16) and $FF;
// Format the result
Result := 'R('+IntToStr(r)+') G('+IntToStr(g)+') G('+IntToStr(b)+')';
{
Alternatively, format the result as follows to get a
string representation of the Delphi TColor value
Result := ColorToString(GetPixel(dc,curP.X,curP.Y));
}
end;
var
s: string;
P: TPoint;
begin
s := '';
Writeln('Move mouse over a pixel. Hit return to get colour of selected pixel.');
repeat
Readln(s);
if s = '' then
begin
GetCursorPos(P);
Writeln('Colour at cursor position X:'+
IntToStr(P.X)+' Y:'+
IntToStr(P.Y) +' = '+
GetPixelColourAsString(P)
);
Writeln('');
Writeln('Move mouse and hit enter again.');
end;
until
SameText(s,'quit');
end.
Example output:
Move mouse over a pixel. Hit return to get colour of selected pixel.
Colour at cursor position X:429 Y:161 = R(0) G(0) B(0)
Move mouse and hit enter again.
Colour at cursor position X:942 Y:358 = R(182) G(206) B(231)
Move mouse and hit enter again.
Colour at cursor position X:704 Y:103 = R(240) G(240) B(240)
Move mouse and hit enter again.
Colour at cursor position X:2756 Y:59 = R(250) G(196) B(182)
=={{header|F_Sharp|F#}}==
open System.Drawing open System.Windows.Forms let GetPixel x y = use img = new Bitmap(1,1) use g = Graphics.FromImage(img) g.CopyFromScreen(new Point(x,y), new Point(0,0), new Size(1,1)) let clr = img.GetPixel(0,0) (clr.R, clr.G, clr.B) let GetPixelAtMouse () = let pt = Cursor.Position GetPixel pt.X pt.Y
Go
{{libheader|RobotGo}}
package main import ( "fmt" "github.com/go-vgo/robotgo" ) func main() { // get position of mouse cursor x, y := robotgo.GetMousePos() // get color of pixel at that position color := robotgo.GetPixelColor(x, y) fmt.Printf("Color of pixel at (%d, %d) is 0x%s\n", x, y, color) }
{{out}} Sample output:
Color of pixel at (659, 253) is 0x300a24
=={{header|Icon}} and {{header|Unicon}}== Icon and Unicon don't have direct access to the screen; however, we can read the colour of of a maximal sized window instead. The graphics procedure generates all pixels from a rectangular selection as a comma separated string with RGB values.
link graphics,printf
procedure main()
WOpen("canvas=hidden") # hide for query
height := WAttrib("displayheight") - 45 # adjust for ...
width := WAttrib("displaywidth") - 20 # ... window 7 borders
WClose(&window)
W := WOpen("size="||width||","||height,"bg=black") |
stop("Unable to open window")
every 1 to 10 do { # generate some random rectangles within the frame
x := ?width
y := ?(height-100)
WAttrib("fg="||?["red","green","blue","purple","yellow"])
FillRectangle(x,x+50,y,y+50)
}
while Event() do
printf("x=%d,y=%d pixel=%s\n",&x,&y,Pixel(&x,&y,&x,&y))
WDone(W) # q to exit
end
{{libheader|Icon Programming Library}} [http://www.cs.arizona.edu/icon/library/src/procs/graphics.icn graphics.icn provides graphics] [http://www.cs.arizona.edu/icon/library/src/procs/printf.icn printf.icn provides printf]
Sample Output:
x=943,y=946 pixel=0,0,65535
x=658,y=610 pixel=47802,0,65535
x=934,y=487 pixel=0,0,0
Java
{{uses from|AWT|Robot}}
public static Color getColorAt(int x, int y){ return new Robot().getPixelColor(x, y); }
Julia
# Windows GDI version function getpixelcolors(x, y) hdc = ccall((:GetDC, "user32.dll"), UInt32, (UInt32,), 0) pxl = ccall((:GetPixel, "gdi32.dll"), UInt32, (UInt32, Cint, Cint), hdc, Cint(x), Cint(y)) return pxl & 0xff, (pxl >> 8) & 0xff, (pxl >> 16) & 0xff end const x = 120 const y = 100 cols = getpixelcolors(x, y) println("At screen point (x=$x, y=$y) the color RGB components are red: $(cols[1]), green: $(cols[2]), and blue: $(cols[3])")
{{output}}
At screen point (x=120, y=100) the color RGB components are red: 1, green: 36, and blue: 86
Kotlin
import java.awt.* fun getMouseColor(): Color { val location = MouseInfo.getPointerInfo().location return getColorAt(location.x, location.y) } fun getColorAt(x: Int, y: Int): Color { return Robot().getPixelColor(x, y) }
Lingo
{{libheader|ScrnXtra3 Xtra}}
on getScreenPixelColor (x, y)
sx = xtra("ScrnXtra3").new()
img = sx.ScreenToImage(rect(x, y, x+1, y+1))
return img.getPixel(0, 0)
end
Logo
CLEARSCREEN SHOW PIXEL [255 255 255]
M2000 Interpreter
Colors is M2000 have a negative value for RGB, or positive for default colors (0 to 15 are the default colors). Also numbers above 0x80000000 (is a positive number), are Windows colors too. Point return a negative value so we have to make it positive to get the RGB value where Red is the least significant byte. Html color has R as the most significant byte (of three), so to display properly we have to use a mix of Right$(),Mid$() and Left$() functions on string representation on color$.
Module CheckColor {
\\ Print hex code for color, and html code for color
Every 25 {
move mouse.x, mouse.y
color$=Hex$(-point, 3) ' point has a negative value
Print Over "0x"+color$+", #"+Right$(color$,2)+Mid$(color$, 3,2)+Left$(color$,2)
if mouse<>0 then exit
}
Print
}
CheckColor
Mathematica
getPixel[{x_?NumberQ, y_?NumberQ}, screenNumber_Integer: 1] := ImageValue[CurrentScreenImage[n], {x, y}]
Nim
{{libheader|GTK2}}
import gtk2, gdk2, gdk2pixbuf gtk2.nim_init() proc getPixelColor(x, y: int32): auto = var p = pixbufNew(COLORSPACE_RGB, false, 8, 1, 1) discard p.getFromDrawable(getDefaultRootWindow().Drawable, getDefaultScreen().getSystemColormap(), x, y, 0, 0, 1, 1) result = cast[tuple[r, g, b: uint8]](p.getPixels[]) echo getPixelColor(0, 0)
Phix
{{libheader|pGUI}}
integer {r,g,b} = im_pixel(image, x, y)
An example of this in use can be found in demo/pGUI/simple_paint.exw
PHP
{{works with|PHP|5.2.2}} {{works with|Windows}} {{libheader|GD}}
$img = imagegrabscreen();
$color = imagecolorat($im, 10, 50);
imagedestroy($im);
PicoLisp
Using '[http://www.muquit.com/muquit/software/grabc/grabc.html grabc]' as recommended in the C solution
(in '(grabc)
(mapcar hex (cdr (line NIL 1 2 2 2))) )
Output:
73,61,205
-> (73 61 205)
Processing
Access any pixel value on the sketch canvas. A color in Processing is a 32-bit int, organized in four components, alpha red green blue, as AAAAAAAARRRRRRRRGGGGGGGGBBBBBBBB. Each component is 8 bits (a number between 0 and 255), and can be accessed with alpha(), red(), green(), blue().
void draw(){
color c = get(mouseX,mouseY);
println(c, red(c), green(c), blue(c));
}
For greater speed, pixels may be looked up by index in the pixels[] array, and color components may be retrieved by bit-shifting.
void draw(){
loadPixels();
color c = pixels[mouseY * width + mouseX];
println(c, c >> 16 & 0xFF, c >> 8 & 0xFF, c >> 8 & 0xFF);
}
Python
{{libheader|PyWin32}}
def get_pixel_colour(i_x, i_y): import win32gui i_desktop_window_id = win32gui.GetDesktopWindow() i_desktop_window_dc = win32gui.GetWindowDC(i_desktop_window_id) long_colour = win32gui.GetPixel(i_desktop_window_dc, i_x, i_y) i_colour = int(long_colour) return (i_colour & 0xff), ((i_colour >> 8) & 0xff), ((i_colour >> 16) & 0xff) print get_pixel_colour(0, 0)
{{libheader|PIL}}
{{works_with|Windows}} only
def get_pixel_colour(i_x, i_y): import PIL.ImageGrab return PIL.ImageGrab.grab().load()[i_x, i_y] print get_pixel_colour(0, 0)
{{libheader|PIL}} {{libheader|python-xlib}}
def get_pixel_colour(i_x, i_y): import PIL.Image # python-imaging import PIL.ImageStat # python-imaging import Xlib.display # python-xlib o_x_root = Xlib.display.Display().screen().root o_x_image = o_x_root.get_image(i_x, i_y, 1, 1, Xlib.X.ZPixmap, 0xffffffff) o_pil_image_rgb = PIL.Image.fromstring("RGB", (1, 1), o_x_image.data, "raw", "BGRX") lf_colour = PIL.ImageStat.Stat(o_pil_image_rgb).mean return tuple(map(int, lf_colour)) print get_pixel_colour(0, 0)
{{libheader|PyGTK}}
def get_pixel_colour(i_x, i_y): import gtk # python-gtk2 o_gdk_pixbuf = gtk.gdk.Pixbuf(gtk.gdk.COLORSPACE_RGB, False, 8, 1, 1) o_gdk_pixbuf.get_from_drawable(gtk.gdk.get_default_root_window(), gtk.gdk.colormap_get_system(), i_x, i_y, 0, 0, 1, 1) return tuple(o_gdk_pixbuf.get_pixels_array().tolist()[0][0]) print get_pixel_colour(0, 0)
{{libheader|PyQt}}
def get_pixel_colour(i_x, i_y): import PyQt4.QtGui # python-qt4 app = PyQt4.QtGui.QApplication([]) long_qdesktop_id = PyQt4.QtGui.QApplication.desktop().winId() long_colour = PyQt4.QtGui.QPixmap.grabWindow(long_qdesktop_id, i_x, i_y, 1, 1).toImage().pixel(0, 0) i_colour = int(long_colour) return ((i_colour >> 16) & 0xff), ((i_colour >> 8) & 0xff), (i_colour & 0xff) print get_pixel_colour(0, 0)
Racket
See [https://github.com/zdhickman/rosetta-code/blob/master/get-pixel-color.rkt get-pixel-color.rkt].
REXX
This program ''only'' works ::* Personal REXX or ::* PC/REXX
This REXX version uses the position of the cursor.
The REXX program converts the hexadecimal attribute of the character at the location of the cursor to a familiar name of a color.
/*REXX program obtains the cursor position (within it's window) and displays it's color.*/
parse value cursor() with r c . /*get cursor's location in DOS screen. */
hue=scrRead(r, c, 1, 'A') /*get color of the cursor's location. */
if hue=='00'x then color= 'black' /*or dark grey, dark gray. */
if hue=='01'x then color= 'darkblue'
if hue=='02'x then color= 'darkgreen'
if hue=='03'x then color= 'darkturquoise' /*or dark cyan. */
if hue=='04'x then color= 'darkred' /*or maroon. */
if hue=='05'x then color= 'darkmagenta' /*or dark pink. */
if hue=='06'x then color= 'orange' /*or dark yellow, orage, brown. */
if hue=='07'x then color= 'gray' /*or grey, gray, dark white. */
if hue=='08'x then color= 'gray' /*or grey, gray, dark white. */
if hue=='09'x then color= 'blue' /*or bright blue. */
if hue=='0A'x then color= 'green' /*or bright green. */
if hue=='0B'x then color= 'turquoise' /*or bright turquoise, cyan, britecyan.*/
if hue=='0C'x then color= 'red' /*or bright red. */
if hue=='0D'x then color= 'magenta' /*or bright magenta, pink, brite pink. */
if hue=='0E'x then color= 'yellow' /*or bright yellow. */
if hue=='0F'x then color= 'white' /*or bright, brite white. */
say 'screen location ('r","c') color is:' color /*display color of char at row, column.*/
{{out|output}}
screen location (33,1) color is: yellow
Ring
# Project : Color of a screen pixel
Load "gamelib.ring"
r = 0
g = 0
b = 0
al_init()
al_init_image_addon()
display = al_create_display(1000,800)
al_set_target_bitmap(al_get_backbuffer(display))
al_clear_to_color(al_map_rgb(255,255,255))
image = al_load_bitmap("stock.jpg")
al_draw_rotated_bitmap(image,0,0,250,250,150,0)
al_draw_scaled_bitmap(image,0,0,250,250,20,20,400,400,0)
ring_getpixel(image,300,300)
see "r = " + r + nl
see "g = " + g + nl
see "b = " + b + nl
al_flip_display()
al_rest(2)
al_destroy_bitmap(image)
al_destroy_display(display)
func ring_getpixel(image,x,y)
newcolor = al_get_pixel(image,x,y)
r=copy(" ",4) g=copy(" ",4) b=copy(" ",4)
p1 = VarPtr("r","float")
p2 = VarPtr("g","float")
p3 = VarPtr("b","float")
al_unmap_rgb_f(newcolor, p1 , p2 , p3 )
r = bytes2float(r)
g = bytes2float(g)
b = bytes2float(b)
return [r,g,b]
Output:
r = 0.42
g = 0.29
b = 0.27
Ruby
This example requires ImageMagick >= 6.2.10 (works on X11, unsure about other platforms).
module Screen IMPORT_COMMAND = '/usr/bin/import' # Returns an array with RGB values for the pixel at the given coords def self.pixel(x, y) if m = `#{IMPORT_COMMAND} -silent -window root -crop 1x1+#{x.to_i}+#{y.to_i} -depth 8 txt:-`.match(/\((\d+),(\d+),(\d+)\)/) m[1..3].map(&:to_i) else false end end end
Scala
{{libheader|Scala}}
def getColorAt(x: Int, y: Int): Color = new Robot().getPixelColor(x, y)
Tcl
{{libheader|Tk}} Works only on X11 or OSX with Xquartz.
package require Tcl 8.5 package require Tk # Farm out grabbing the screen to an external program. # If it was just for a Tk window, we'd use the tkimg library instead proc grabScreen {image} { set pipe [open {|xwd -root -silent | convert xwd:- ppm:-} rb] $image put [read $pipe] close $pipe } # Get the RGB data for a particular pixel (global coords) proc getPixelAtPoint {x y} { set buffer [image create photo] grabScreen $buffer set data [$image get $x $y] image delete $buffer return $data } # Demo... puts [format "pixel at mouse: (%d,%d,%d)" \ {*}[getPixelAtPoint {*}[winfo pointerxy .]]]
XPL0
Color gets either 1, 2, 4, 8, 15, 16, or 24 significant bits depending on the current graphic mode enabled on an IBM-PC compatible machine with VESA graphics.
code ReadPix=44;
int Color, X, Y;
Color:= ReadPix(X, Y);
{{omit from|ACL2}} {{omit from|AWK|Does not have this functionality in the language}} {{omit from|Batch File|No access to GUI functions}} {{omit from|Blast}} {{omit from|Brainfuck}} {{omit from|GUISS}} {{omit from|Lilypond}} {{omit from|Logtalk}} {{omit from|Lotus 123 Macro Scripting}} {{omit from|Maxima}} {{omit from|MUMPS}} {{omit from|PARI/GP}} {{omit from|PostScript}} {{omit from|R}} {{omit from|Stata}} {{omit from|TPP}} {{omit from|UNIX Shell}}