DianaSimona

Thank you for your replies! What i was trying to do is obtain a pure black and white image as i did in matlab (using a threshold value), but i was quite unsure on how to implement that in php. I will try using the tips provided! Thanks again 😀

I'm trying to convert a grayscale image to pure black and white in php using the GD library. The purpose would be to detect the cervical cells within the image. I'll leave the php code and a matlab one (i wrote this code in matlab and i'm trying to obtain the same result in php). Basically, im having troubles accessing each individual pixel's color and modifying it. MATLAB: clear all, clc, close all; I = imread('celule.jpg'); imshow(I) title('original'); a=rgb2gray(I); figure; imshow(a) title('grayscale'); s=size(a); for i=1:s(1) for j=1:s(2) if a(i,j)>190 a(i,j)=0; else a(i,j)=255; end end end figure; imshow(a) title('pure black and white'); PHP: <?php $im = imagecreatefromjpeg("celule.jpg"); function imagetograyscale($im) { if (imageistruecolor($im)) { imagetruecolortopalette($im, false, 256); } for ($c = 0; $c < imagecolorstotal($im); $c++) { $col = imagecolorsforindex($im, $c); $gray = round(0.299 * $col['red'] + 0.587 * $col['green'] + 0.114 * $col['blue']); imagecolorset($im, $c, $gray, $gray, $gray); } } imagetograyscale($im); //imagefilter($im, IMG_FILTER_CONTRAST, -255); //i'm not looking for this effect header('Content-type: image/jpeg'); imagejpeg($im); $C = imagesx($im); //width $L = imagesy($im); //height echo "Dimensiuni imagine: latime $C, inaltime $L <br>"; //scanning through the image for($x = 0; $x < $L; $x++) { //each line for($y = 0; $y < $C; $y++) { //each collumn // pixel color at (x, y) $color = imagecolorat($im, $y, $x); $color = imagecolorsforindex($im, $color); //getting rgb values $RED[$x][$y] = $color["red"]; //each rgb component $GREEN[$x][$y] = $color["green"]; $BLUE[$x][$y] = $color["blue"]; } } ?> image "celule.jpg": https://i.ibb.co/6Ffj6sc/celule.jpg