Dtyjlui

I am looking for a tool that lets me select any pixel on the screen and get its RGB color and absolute (x, y) location.

I have used tools on Windows that show a large magnified square with a crosshair letting me easily select the pixel I want and get its details.

Is there anything like this for ubuntu?

The best fit is...a tiny Windows tool called ColorPix (via WINE)

After searching long and hard, it appears none of the available tools for Ubuntu/Linux fulfill both your criteria, i.e. magnification and coordinate display.

So we go for a tiny Windows tool that -- critically -- just works with a default WINE install, no configuration, installation, DLLs, etc. needed.

• 
  

  It features adjustable zoom, one-click copy in multiple formats and co-ordinate display:

  
  
  

  

  
  

1. Install Wine

sudo apt-get install wine

(that's it!)

2. Download ColorPix

ColorPix can be officially downloaded as a tiny, portable 600KB exe here

I suggest downloading directly to your local binaries directory with:

sudo wget -O/usr/local/bin/ColorPix.exe http://www.colorschemer.com/ColorPix.exe

3. Create a launcher for ColorPix

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  Let's get an icon first:

  
  
  

  sudo wget -O/usr/share/icons/colorpix.png http://cdn.alternativeto.net/i/22e49edc-efa7-e011-979d-0025902c7e73_11865.png
  
  

  
  


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  Press Alt+F2 now and type gksudo gedit /usr/share/applications/colorpix.desktop, and paste the below and save the file:

  
  
  

  
  
  [Desktop Entry]
  
  Name=ColorPix
  
  GenericName=ColorPix
  
  Comment=ColorPicker via WINE
  
  Exec=wine /usr/local/bin/ColorPix.exe
  
  Terminal=false
  
  Icon=/usr/share/icons/colorpix.png
  
  Type=Application
  
  StartupNotify=true
  
  

  
  


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  From a terminal, run:

  
  
  

  sudo chmod +x /usr/share/applications/colorpix.desktop
  
  

  
  


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  In a few seconds, it will be available in the launcher as:

  
  
  

  

  
  

4. Using ColorPix

Start it, and the very first time it may take a few seconds while WINE initializes.

The screenshot below shows it in action, with:

• The coordinates on the top


• Color values in different formats below (click to copy to clipboard)


• Adjustable magnifier below


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  Press any key once you are on your desired pixel to lock values

  
  
  

  

  
  

There is a tool called gpick.

Here you can see an image of the tool. With gpick you can select pixels, see the HTML code, add colors to the palette and generate colors.

To use it, right click the middle of the hexagon then use space bar to save colors into the palette.

This will get you what you want I believe. Admittedly it is a few steps but it looks worse than it is since I showed each little step.

Setup

Install ImageMagick & Shutter.

sudo apt-get install imagemagick shutter

How to get the x,y coordinates and color

A. Open Shutter and click the selection button

B. Note that as you move your mouse around it will show you the x,y coordinates you are looking for.

When you've got the right place go ahead and click with your mouse button and draw a square to capture an image. (It doesn't really matter how large your image is just so long as you start it (top left corner) on the pixel of interest.)

C. Close the image in shutter

D. Run the following command from the terminal. This will give you the color values of the top left pixel.

convert ~/Pictures/Selection_001.png -crop 1x1+1+1 txt:- | sed -n 's/.* (#.*)/1/p' 

E. While in the command line go ahead and delete the image so that the next time shutter takes a picture it gives it the same name. (Otherwise you'll need to adjust the name in the previous step (D).

rm ~/Pictures/Selection_001.png

Paste this code into a text editor, make it executable and run it. When you choose a color with the eyedropper, the x and y coordinates will appear at the top.

Edit: Wrote code to add a zoom window. To have it grab pixels outside of the window click the button (not the eyedropper). Click the button again to stop grabbing the pointer. Haven’t figured out how to draw a crosshair with cairo, but you can probably use as is. I left some cairo code in there in case someone can tell me why my rectangle doesn’t draw…

#!/usr/bin/python

from gi.repository import Gtk,Gdk, GdkPixbuf

import cairo



class picker(Gtk.Window):

    def __init__(self):

        Gtk.Window.__init__(self)

        self.connect('delete-event', Gtk.main_quit)

        self.connect('motion-notify-event', self.motion_cb)

        self.connect('button-press-event',self.button_press)

        box=Gtk.Box(orientation=Gtk.Orientation.HORIZONTAL)



        #Setup area for coordinates and zoom window

        coordbox=Gtk.Box(orientation=Gtk.Orientation.VERTICAL)

        self.xcoor=Gtk.Label("x: ")

        coordbox.pack_start(self.xcoor, True, False, 1)

        self.ycoor=Gtk.Label("y: ")

        coordbox.pack_start(self.ycoor, True, False, 1)

        self.zoomwin=Gtk.Image()

        #Trying to draw on Gtk.Image with cairo for crosshairs... Not working

        self.zoomwin.connect('draw', self.draw) 

        self.zoomwin.set_app_paintable(True)

        coordbox.pack_start(self.zoomwin,True,True,1)

        self.buttongo=Gtk.Button("Pick Color")

        self.buttongo.connect('clicked',self.gobutton_activate)

        coordbox.pack_start(self.buttongo,True,True,1)

        box.pack_start(coordbox, True, False, 5)



        #Put in color wheel for tweaking color

        self.cp=Gtk.ColorSelection()

        self.cp.connect('color-changed', self.on_color_changed)

        box.pack_start(self.cp, True, True, 5)

        self.add(box)

        self.show_all()



        #Set some initial parameters

        self.w,self.h=10,10 #Size of zoomed image in pixels

        self.count=0

        self.window=self.get_window()

        #set initial zoom image

        self.zoomwin.set_from_pixbuf(self.get_image().scale_simple(240,240,GdkPixbuf.InterpType.TILES))

        self.grabbing=False



    def on_color_changed(self,widget=None, data=None):

        #Print out x,y to widgets

        display=Gdk.Display.get_default()

        (screen,x,y,modifier)=display.get_pointer()

        self.xcoor.set_text("x: %i" %x)

        self.ycoor.set_text("y: %i" %y)





    def get_image(self,w=None,h=None):

        #Get a pixbuff image under pointer

        if w==None: w=self.w

        if h==None: h=self.h

        display=Gdk.Display.get_default()

        (screen,self.x,self.y,modifier)=display.get_pointer()

        window=Gdk.get_default_root_window()

        screenshot = Gdk.pixbuf_get_from_window(window,

            self.x-int(w/2), self.y-int(h/2), int(w), int(h))

        return screenshot



    def motion_cb(self, widget, data):

        #What to do while mouse pointer is moving

        #DONT capture every event! Causes too much backup

        if self.count==5:

            self.pixbuf=self.get_image().scale_simple(240,240,GdkPixbuf.InterpType.TILES)

            self.zoomwin.set_from_pixbuf(self.pixbuf)

            self.zoomwin.queue_draw()

            self.count=0

        self.count+=1



    def grab_start(self):

        #Grab control of pointer outside of window

        self.grabbing = True

        Gdk.pointer_grab(self.window, 

                        True, #allow passage of pointer events to children

                        Gdk.EventMask.POINTER_MOTION_MASK | Gdk.EventMask.BUTTON_PRESS_MASK | Gdk.EventMask.BUTTON_RELEASE_MASK,

                        None,

                        None,# could put a custom cursor here

                        0L)



    def button_press(self,widget,data):

        #capture color under the pointer and set the color selection

        cenpx=self.get_image(1,1)

        color=tuple(map(ord, cenpx.get_pixels()[:3]))

        col=Gdk.RGBA(float(color[0])/256.,float(color[1])/256.,float(color[2])/256.)

        self.cp.set_current_rgba(col)



    def grab_stop(self):

        #Stop Grabbing the pointer

        Gdk.pointer_ungrab(0)

        self.grabbing=False     



    def gobutton_activate(self, widget, data=None):

        #Button control

        if self.grabbing==False:

            self.grab_start()

            widget.set_label("Stop Picking")

        else:

            self.grab_stop()

            widget.set_label("Pick Color")



    def draw(self, widget, cr):

        #this gets called, but nothing is drawn that I can see...

        cr.set_operator(cairo.OPERATOR_SOURCE)

        cr.set_source_rgba(1,1,1,1)

        w = self.w

        h = self.h

        cr.set_source_rgba(1,1,1,1)

        cr.set_line_width(10)

        cr.rectangle(w/2-1,h/2-1,w/2+1,h/2+1)

        cr.stroke()

        cr.set_operator(cairo.OPERATOR_OVER)





if __name__=="__main__":

    win=picker()

    Gtk.main()