remove all color but red, then replace it with black

[kucingkembar]

hi, sorry for my bad English,
I googling it for hours and still don't understand how this thing works,

I like to remove all non-red of an image, then replace the red color with black,
this is the working syntax using software called ImageMagick,

convert "%~1" -fill white -fuzz 25%% +opaque red -fill black -opaque red "%~dpn1.Temp%~x1"

but I want the script 100% of python(and its packages),
so please anyone, help me

[Axel_Erfurt]

There is PythonMagick

[DPaul]

Hi,

Red is RGB (255,0,0)
Or do you mean only the R in rgb ?

But I don't understand the question.
If you "remove all non- red", what do you replace it with ?
Then you are going to replace the (255,0,0) with black (0,0,0) ?

If we know what you want to do, it should be easy, probably using Pillow and numpy.

Paul

[snippsat]

PythonMagick as posted is outdated.
Wand is and updated and simple ImageMagick binding.

[kucingkembar]

thank you to all who replied,
to be honest, if there is any solid tutorial I will not ask here

@Axel_Erfurt can you show me how it works

@DPaul I can't really explain it, just imagine there is a jpeg of a rainbow with white background, then except red, removal all the all of color line with white, then replace red color with black, the result is a line color of black, (if I can reply with images from my PC I will upload it)
if using Pillow and NumPy. can do it, please tell me how to do it

@snippsat please tell me how to do it

[BashBedlam]

I got pretty close. Perhaps you can tweek it a little further.

from PIL import Image
import numpy as np
img = Image.open('color_field.jpg')
width = img.size[0] 
height = img.size[1] 
for i in range(0,width):# process all pixels
	for j in range(0,height):
		data = img.getpixel((i,j))
		if data[0] < 235 :
			img.putpixel((i,j),(255, 255, 255))
		else :
			img.putpixel((i,j),(0, 0, 0))
img.show()

[kucingkembar]

thank you BashBedlam for the reply
when I tried pic from your sample it worked great,
but when I tried it using random jpeg pictures, the result is not good,

sorry out of topic, how did you attach pictures? can you upload directly from your PC?

[DPaul]

but when I tried it using random jpeg pictures, the result is not good,

Well, if you throw away all colors except 1 and replace that with black...
It's not a work of art that is going to emerge.

Except if what you really want is to convert a picture into Black & white.
That is a slightly different ptocedure. The simplest form is to do x = (R+G+B)/3
for every pixel. R=x,G=x,B=x

It could also be that you are attempting a B&W conversion, using only the red channel.
That is possible, but then you need to do R=R, G=R, B=R

Paul

[kucingkembar]

thank you for the reply DPaul,
sorry if I am rude and quite stupid,
can you provide the code, please

[kucingkembar]

after researching the code BashBedlam provide,
I edit it and the code is working as I intended

from PIL import Image
import numpy as np
imgT = Image.open('rainbow.png')
img = imgT.convert("RGB")
width = img.size[0] 
height = img.size[1] 
for i in range(0,width):# process all pixels
    for j in range(0,height):
        data = img.getpixel((i,j))
        # data[0] = Red,  [1] = Green, [2] = Blue
        # data[0,1,2] range = 0~255
        if data[0] > 150 and data[1] < 50 and data[2] < 50 :
            #put black
            img.putpixel((i,j),(0, 0, 0))
        else :
            #Put white
            img.putpixel((i,j),(255, 255, 255))
img.show()

thank you again for all who reply, stay healthy and have a nice day