help invert color

gimptest · **Joined:** Feb 21, 2016 **Posts:** 34

How to write invert Colos in the SCM code, but instead of calling the plugin in the Invert.

I tried to use (gimp-drawable-get-pixel drawable x-Coord y-Coord) for each pixel value, again with 255 minus the per-pixel values, and then use the (gimp-drawable-set-pixel drawable x-Coord y-Coord) to redraw, but in execution (GIMP-drawable-get-pixel drawable X-Coord y-Coord) when an error do not know how to extract the RGB value, please advise. Or a complete SCM code available for reference.

Attachment:

snip_20160529172759.png [ 31.31 KiB | Viewed 3034 times ]

dinasset · **Posted:** Sun May 29, 2016 8:47 am **(#2)**

just a piece of the script you want, only to show how to access independently R,G,B values

Code: Select all

(define (script-fu-test-color-by-pixel
         image
         drawable
       )
  (let*
   (
     (RGBvalues '(0 0 0))
     (REDvalue 0)
     (GREENvalue 0)
     (BLUEvalue 0)
   )
  (set! RGBvalues (cadr (gimp-drawable-get-pixel drawable 100 100)))
  (set! REDvalue  (aref RGBvalues 0))
  (set! GREENvalue  (aref RGBvalues 1))
  (set! BLUEvalue  (aref RGBvalues 2))
  (gimp-message (string-append "RED = " (number->string REDvalue)))
  
  ;;; and so on ....
  
  ) ; end let
) ; end define

(script-fu-register "script-fu-test-color-by-pixel"
            _"<Image>/Script-Fu/Test/test-color-by-pixel"
            "test getting RGB from a pixel"
            "D.N"
            "2016"
            "2016"
            "RGB*"
            SF-IMAGE        "Image"     0
            SF-DRAWABLE     "Drawable"  0
)
  

gimptest · **Joined:** Feb 21, 2016 **Posts:** 34

dinasset wrote:

just a piece of the script you want, only to show how to access independently R,G,B values

Code: Select all

(define (script-fu-test-color-by-pixel
         image
         drawable
       )
  (let*
   (
     (RGBvalues '(0 0 0))
     (REDvalue 0)
     (GREENvalue 0)
     (BLUEvalue 0)
   )
  (set! RGBvalues (cadr (gimp-drawable-get-pixel drawable 100 100)))
  (set! REDvalue  (aref RGBvalues 0))
  (set! GREENvalue  (aref RGBvalues 1))
  (set! BLUEvalue  (aref RGBvalues 2))
  (gimp-message (string-append "RED = " (number->string REDvalue)))
  
  ;;; and so on ....
  
  ) ; end let
) ; end define

(script-fu-register "script-fu-test-color-by-pixel"
            _"<Image>/Script-Fu/Test/test-color-by-pixel"
            "test getting RGB from a pixel"
            "D.N"
            "2016"
            "2016"
            "RGB*"
            SF-IMAGE        "Image"     0
            SF-DRAWABLE     "Drawable"  0
)
  

Thank dinasset.

dinasset · **Posted:** Sun May 29, 2016 11:56 am **(#4)**

Take it as an exercise, because there is no reason to manage pixel by pixel an image using scheme, it will require a huge amount of time.
I recommend you to use python instead with the use of tiles, extremely faster.
You may take as a base my filter remove-overpainted-colours.py here
You will need to change only a few statements to "invert the colours".
I can't follow you during the next days, because I'm going out for week or so.
But you may try and -if necessary- we will be again in touch when I'll be back.

gimptest · **Joined:** Feb 21, 2016 **Posts:** 34

dinasset wrote:

Take it as an exercise, because there is no reason to manage pixel by pixel an image using scheme, it will require a huge amount of time.
I recommend you to use python instead with the use of tiles, extremely faster.
You may take as a base my filter remove-overpainted-colours.py here
You will need to change only a few statements to "invert the colours".
I can't follow you during the next days, because I'm going out for week or so.
But you may try and -if necessary- we will be again in touch when I'll be back.

Thank dinasset, but I can not open this page.

dinasset · **Posted:** Sun May 29, 2016 12:17 pm **(#6)**

click on Latest GIMP Scripts & Plug-ins (top area of this panel)
search on the left the most recent addition
you should find the link

dinasset · **Posted:** Sun May 29, 2016 12:21 pm **(#7)**

BTW, on my previous message, did you click on the word "here"?

gimptest · **Joined:** Feb 21, 2016 **Posts:** 34

dinasset wrote:

BTW, on my previous message, did you click on the word "here"?

I see it, but I based on network constraints, can not open website you said.

dinasset · **Posted:** Sun May 29, 2016 12:34 pm **(#9)**

which kind of network constraint?

gimptest · **Joined:** Feb 21, 2016 **Posts:** 34

dinasset wrote:

which kind of network constraint?

Network provider, firewall policy reasons, cannot open certain Web sites

dinasset · **Posted:** Sun May 29, 2016 12:47 pm **(#11)**

this info should be addressed to the Moderators, hope they can solve that problem.
Create a new thread (Help/ Site Support) to address this issue directly to the site moderators

Wallace · **Posted:** Sun May 29, 2016 2:36 pm **(#12)**

gimptest wrote:

dinasset wrote:

which kind of network constraint?

Network provider, firewall policy reasons, cannot open certain Web sites

dinasset wrote:

this info should be addressed to the Moderators, hope they can solve that problem.
Create a new thread (Help/ Site Support) to address this issue directly to the site moderators

It seems as though this is a "Network Provider Firewall Policy".
As was stated by gimptest.
If gimptest's Network Provider doesn't allow some traffic in particular to it's own Firewall Policies.
This has nothing to do with Gimp Chat or the Gimp Scripts website.
Gimp Chat nor the Gimp Scripts website;
can not possibly accommodate every "Network Provider's Fire Wall Policies".
This would be something which gimptest would need to circumvent on his own,
or with the help of his Network Provider.

gimptest · **Joined:** Feb 21, 2016 **Posts:** 34

dinasset wrote:

this info should be addressed to the Moderators, hope they can solve that problem.
Create a new thread (Help/ Site Support) to address this issue directly to the site moderators

Only network providers set limits

gimptest · **Joined:** Feb 21, 2016 **Posts:** 34

Wallace wrote:

gimptest wrote:

dinasset wrote:

which kind of network constraint?

Network provider, firewall policy reasons, cannot open certain Web sites

dinasset wrote:

this info should be addressed to the Moderators, hope they can solve that problem.
Create a new thread (Help/ Site Support) to address this issue directly to the site moderators

It seems as though this is a "Network Provider Firewall Policy".
As was stated by gimptest.
If gimptest's Network Provider doesn't allow some traffic in particular to it's own Firewall Policies.
This has nothing to do with Gimp Chat or the Gimp Scripts website.
Gimp Chat nor the Gimp Scripts website;
can not possibly accommodate every "Network Provider's Fire Wall Policies".
This would be something which gimptest would need to circumvent on his own,
or with the help of his Network Provider.

Yes, access to certain websites had to use a VPN, but use the VPN is also sometimes can and sometimes cannot be

gimptest · **Joined:** Feb 21, 2016 **Posts:** 34

dinasset wrote:

just a piece of the script you want, only to show how to access independently R,G,B values

Code: Select all

(define (script-fu-test-color-by-pixel
         image
         drawable
       )
  (let*
   (
     (RGBvalues '(0 0 0))
     (REDvalue 0)
     (GREENvalue 0)
     (BLUEvalue 0)
   )
  (set! RGBvalues (cadr (gimp-drawable-get-pixel drawable 100 100)))
  (set! REDvalue  (aref RGBvalues 0))
  (set! GREENvalue  (aref RGBvalues 1))
  (set! BLUEvalue  (aref RGBvalues 2))
  (gimp-message (string-append "RED = " (number->string REDvalue)))
  
  ;;; and so on ....
  
  ) ; end let
) ; end define

(script-fu-register "script-fu-test-color-by-pixel"
            _"<Image>/Script-Fu/Test/test-color-by-pixel"
            "test getting RGB from a pixel"
            "D.N"
            "2016"
            "2016"
            "RGB*"
            SF-IMAGE        "Image"     0
            SF-DRAWABLE     "Drawable"  0
)
  

I'm using (gimp-drawable-set-pixel drawable x-Coord y-Coord NUM-channels pixel), parameter error, don't know how this argument is correct

Attachment:

snip_20160530085704.png [ 32.51 KiB | Viewed 1181 times ]

(define (script-fu-test-color-by-pixel
image
drawable
)
(let*
(
(RGBvalues '(0 0 0))
(REDvalue 0)
(GREENvalue 0)
(BLUEvalue 0)
(numch 0)
)
(set! RGBvalues (cadr (gimp-drawable-get-pixel drawable 100 100)))
(set! numch (car (gimp-drawable-get-pixel drawable 100 100)))
(set! REDvalue (aref RGBvalues 0))
(set! GREENvalue (aref RGBvalues 1))
(set! BLUEvalue (aref RGBvalues 2))
(gimp-message (string-append "RED = " (number->string REDvalue)))
(set! RGBvalues '((- 255 REDvalue) (- 255 GREENvalue) (- 255 BLUEvalue)))
(gimp-drawable-set-pixel drawable 100 numch RGBvalues)
(gimp-displays-flush)

;;; and so on ....

) ; end let
) ; end define

(script-fu-register "script-fu-test-color-by-pixel"
_"<Image>/Script-Fu/Test/test-color-by-pixel"
"test getting RGB from a pixel"
"D.N"
"2016"
"2016"
"RGB*"
SF-IMAGE "Image" 0
SF-DRAWABLE "Drawable" 0
)

trandoductin · **Posted:** Sun May 29, 2016 8:37 pm **(#16)**

(gimp-drawable-set-pixel drawable 100 numch RGBvalues)
seems to be missing an x-coord or y-coord

gimptest · **Joined:** Feb 21, 2016 **Posts:** 34

trandoductin wrote:

(gimp-drawable-set-pixel drawable 100 numch RGBvalues)
seems to be missing an x-coord or y-coord

Thank trandoductin
It still doesn't work. (gimp-drawable-set-pixel drawable x-Coord y-Coord NUM-channels pixel) pixel parameters do not know how to write

Attachment:

snip_20160530094605.png [ 31.24 KiB | Viewed 1177 times ]

(define (script-fu-test-color-by-pixel
image
drawable
)
(let*
(
(RGBvalues '(0 0 0))
(REDvalue 0)
(GREENvalue 0)
(BLUEvalue 0)
(numch 0)
(x-coord 100)
(y-coord 100)
)
(set! RGBvalues (cadr (gimp-drawable-get-pixel drawable x-coord y-coord)))
(set! numch (car (gimp-drawable-get-pixel drawable x-coord y-coord)))
(set! REDvalue (aref RGBvalues 0))
(set! GREENvalue (aref RGBvalues 1))
(set! BLUEvalue (aref RGBvalues 2))
(gimp-message (string-append "RED = " (number->string REDvalue)))
(set! RGBvalues '((- 255 REDvalue) (- 255 GREENvalue) (- 255 BLUEvalue)))
(gimp-drawable-set-pixel drawable x-coord y-coord numch RGBvalues)
(gimp-displays-flush)

;;; and so on ....

) ; end let
) ; end define

(script-fu-register "script-fu-test-color-by-pixel"
_"<Image>/Script-Fu/Test/test-color-by-pixel"
"test getting RGB from a pixel"
"D.N"
"2016"
"2016"
"RGB*"
SF-IMAGE "Image" 0
SF-DRAWABLE "Drawable" 0
)

trandoductin · **Posted:** Sun May 29, 2016 10:04 pm **(#18)**

you can't do math in a static list, you'll have to use (list) function to construct a list.
gimp-drawable-set-pixel accepts an array/vector instead of list so you'll have to use (list->vector) function
and also it doesn't update the front end for you to see the change until you call (gimp-drawable-update) or manually hide the layer and show it again.
try sample code below

Code: Select all

(set! RGBvalues (list (- 255 REDvalue) (- 255 GREENvalue) (- 255 BLUEvalue)))
(gimp-drawable-set-pixel drawable x-coord y-coord numch (list->vector RGBvalues))
(gimp-drawable-update drawable 0 0 (car (gimp-drawable-width drawable)) (car (gimp-drawable-height drawable)))

Note: the numch can be a 4 if there's an alpha channel in your layer/drawable, you might want to copy the 4th value over if drawable/layer has alpha.

gimptest · **Joined:** Feb 21, 2016 **Posts:** 34

trandoductin wrote:

you can't do math in a static list, you'll have to use (list) function to construct a list.
gimp-drawable-set-pixel accepts an array/vector instead of list so you'll have to use (list->vector) function
and also it doesn't update the front end for you to see the change until you call (gimp-drawable-update) or manually hide the layer and show it again.
try sample code below

Code: Select all

(set! RGBvalues (list (- 255 REDvalue) (- 255 GREENvalue) (- 255 BLUEvalue)))
(gimp-drawable-set-pixel drawable x-coord y-coord numch (list->vector RGBvalues))
(gimp-drawable-update drawable 0 0 (car (gimp-drawable-width drawable)) (car (gimp-drawable-height drawable)))

Note: the numch can be a 4 if there's an alpha channel in your layer/drawable, you might want to copy the 4th value over if drawable/layer has alpha.

Thank trandoductin
I've added alpha, but didn't know it was still wrong
You can paste the complete code let me reference?

Attachment:

snip_20160530113918.png [ 30 KiB | Viewed 1163 times ]

Code: Select all

(define (script-fu-test-color-by-pixel
         image
         drawable
       )
  (let*
   (
     (RGBvalues '(0 0 0))
     (REDvalue 0)
     (GREENvalue 0)
     (BLUEvalue 0)
    (numch 0)
    (x-coord 100)
     (y-coord 100)
    (alpha (car (gimp-drawable-has-alpha drawable)))
   )
   
  (if (= alpha FALSE) (gimp-layer-add-alpha drawable))
  (set! RGBvalues (cadr (gimp-drawable-get-pixel drawable 100 100)))
  (set! numch (car (gimp-drawable-get-pixel drawable 100 100)))
  (set! REDvalue  (aref RGBvalues 0))
  (set! GREENvalue  (aref RGBvalues 1))
  (set! BLUEvalue  (aref RGBvalues 2))
  (gimp-message (string-append "RED = " (number->string REDvalue)))
  (set! RGBvalues (list (- 255 REDvalue) (- 255 GREENvalue) (- 255 BLUEvalue)))
  (gimp-drawable-set-pixel drawable x-coord y-coord numch (list->vector RGBvalues))
  (gimp-drawable-update drawable 0 0 (car (gimp-drawable-width drawable)) (car (gimp-drawable-height drawable)))

  (gimp-displays-flush)
  
  ;;; and so on ....
  
  ) ; end let
) ; end define

(script-fu-register "script-fu-test-color-by-pixel"
            _"<Image>/Script-Fu/Test/test-color-by-pixel"
            "test getting RGB from a pixel"
            "D.N"
            "2016"
            "2016"
            "RGB*"
            SF-IMAGE        "Image"     0
            SF-DRAWABLE     "Drawable"  0
)
  

trandoductin · **Posted:** Sun May 29, 2016 11:30 pm **(#20)**

try this, it'll check to see if numch is 4 means there's alpha and will also work if there's no alpha channel.

Code: Select all

 (define (script-fu-test-color-by-pixel
image
drawable
)
(let*
(
(RGBvalues 0)
(REDvalue 0)
(GREENvalue 0)
(BLUEvalue 0)
(numch 0)
(x-coord 100)
(y-coord 100)
)
(set! RGBvalues (cadr (gimp-drawable-get-pixel drawable x-coord y-coord)))
(set! numch (car (gimp-drawable-get-pixel drawable x-coord y-coord)))
(set! REDvalue (aref RGBvalues 0))
(set! GREENvalue (aref RGBvalues 1))
(set! BLUEvalue (aref RGBvalues 2))
(define my_pixel (list (- 255 REDvalue) (- 255 GREENvalue) (- 255 BLUEvalue) 255))
(if (= numch 4)
   (begin   ;if numch = 4 means drawable has an alpha channel we just add whatever that is to our pixel
      (set! my_pixel (append my_pixel (list (aref RGBvalues 3))))
   )
   (begin   ;else do nothing
   )
)
;(gimp-message (string-append "RED = " (number->string REDvalue)))
(gimp-drawable-set-pixel drawable x-coord y-coord numch (list->vector my_pixel))
(gimp-drawable-update drawable 0 0 (car (gimp-drawable-width drawable)) (car (gimp-drawable-height drawable)))
(gimp-displays-flush)

;;; and so on ....

) ; end let
) ; end define

(script-fu-register "script-fu-test-color-by-pixel"
_"<Image>/Script-Fu/Test/test-color-by-pixel"
"test getting RGB from a pixel"
"D.N"
"2016"
"2016"
"RGB*"
SF-IMAGE "Image" 0
SF-DRAWABLE "Drawable" 0
) 

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