Skip to main content

Detect colors in images - 20x faster than Numpy

Project description

Detect colors in images - 20 x faster than Numpy

pip install locate-pixelcolor-cpppragma

Tested against Windows 10 / Python 3.10 / Anaconda

Important!

The module imports a function from a compiled .dll (C++). If you get any import errors, install: https://download.visualstudio.microsoft.com/download/pr/8b92f460-7e03-4c75-a139-e264a770758d/26C2C72FBA6438F5E29AF8EBC4826A1E424581B3C446F8C735361F1DB7BEFF72/VC_redist.x64.exe

How to use it in Python

import numpy as np
import cv2
from locate_pixelcolor_cpppragma import search_colors
# 4525 x 6623 x 3 picture https://www.pexels.com/pt-br/foto/foto-da-raposa-sentada-no-chao-2295744/
picx = r"C:\Users\hansc\Downloads\pexels-alex-andrews-2295744.jpg"
pic = cv2.imread(picx)
colors0 = np.array([[255, 255, 255]],dtype=np.uint8)
resus0 = search_colors(pic=pic, colors=colors0, cpus=5)
colors1=np.array([(66,  71,  69),(62,  67,  65),(144, 155, 153),(52,  57,  55),(127, 138, 136),(53,  58,  56),(51,  56,  54),(32,  27,  18),(24,  17,   8),],dtype=np.uint8)
resus1 =  search_colors(pic=pic, colors=colors1, cpus=4)

####################################################################
%timeit resus0 = search_colors(pic=pic, colors=colors0, cpus=5)
23.4 ms ± 40.6 µs per loop (mean ± std. dev. of 7 runs, 10 loops each)

b,g,r = pic[...,0],pic[...,1],pic[...,2]
%timeit np.where(((b==255)&(g==255)&(r==255)))
150 ms ± 209 µs per loop (mean ± std. dev. of 7 runs, 10 loops each)
####################################################################
%timeit resus1 =  search_colors(pic=pic, colors=colors1, cpus=4)
46.6 ms ± 988 µs per loop (mean ± std. dev. of 7 runs, 10 loops each)

%timeit np.where(((b==66)&(g==71)&(r==69))|((b==62)&(g==67)&(r==65))|((b==144)&(g==155)&(r==153))|((b==52)&(g==57)&(r==55))|((b==127)&(g==138)&(r==136))|((b==53)&(g==58)&(r==56))|((b==51)&(g==56)&(r==54))|((b==32)&(g==27)&(r==18))|((b==24)&(g==17)&(r==8)))
1 s ± 16.1 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)
####################################################################

The C++ Code

#include <omp.h>
#include <atomic>  
std::atomic<int> value(0);
int create_id() {
    return value++;
    }

extern "C" __declspec(dllexport) void colorsearch(char *pic, char *colors, int width, int totallengthpic, int totallengthcolor, int *outputx, int *outputy, int *lastresult)
{
    value=0;
    int counter = 0;

#pragma omp parallel reduction(+ \
                               : counter)
    {

#pragma omp for schedule(static)
        for (int i = 0; i <= totallengthcolor; i += 3)
        {
            int r = i;
            int g = i + 1;
            int b = i + 2;
            for (int j = 0; j <= totallengthpic; j += 3)
            {
                if ((colors[r] == pic[j]) && (colors[g] == pic[j + 1]) && (colors[b] == pic[j + 2]))
                {

#pragma omp critical
                    {
                        int dividend = j / 3;
                        int quotient = dividend / width;
                        int remainder = dividend % width;
                        int upcounter = create_id();
                        outputx[upcounter] = quotient;
                        outputy[upcounter] = remainder;
                        lastresult[0] = upcounter;
                    }
                }
            }
        }
    }
}
// Compile:
// cl.exe /std:c++20 /fp:fast /EHsc /MT /Og /Oi /Ot /Oy /Ob3 /GF /Gy /MD /openmp /LD clooppra.cpp /Fe:clooppra.dll
// or
// cl.exe /std:c++20 /fp:fast /EHsc /O2 /MD /openmp /LD clooppra.cpp /Fe:clooppra.dll

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

locate_pixelcolor_cpppragma-0.11.tar.gz (11.1 kB view hashes)

Uploaded Source

Built Distribution

locate_pixelcolor_cpppragma-0.11-py3-none-any.whl (13.6 kB view hashes)

Uploaded Python 3

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page