Question

I am using Ocelot to write a program in JavaScript Our question is below:

Write a function called removeBlueAndGreen that takes an image as an argument and returns a red version of the input image. To do so, create a copy of the input and iterate over each pixel. If the color of a pixel is (r, g, b) in the input image, its color in the output must be (r, 0.0, 0.0).

Now is I write

let robot =

lib220.loadImageFromURL('https://www.bostondynamics.com/sites/default/files/styles/max_1300x1300/public/2019-01/MPM_9703-2.jpg?itok=7fe7RDA7');

for (let i = 0; i < robot.width; ++i) {

for (let j = 0; j < robot.height; ++j) {

robot.setPixel(i, j, [1.0, 0.0, 0.0]);

}

}

robot.show();

But the whole image is red

How would I retrieve the pixels red intensity value and make create a copy of the input and iterate over each pixel? Because with the above code I am turning each pixels red intensity to hard 1.0

Any help would be great!

Answer 1

You have done good so far, the only thing missing in your code is the original R value of the pixel instead of 1.

so, here goes the answer,

let robot =

lib220.loadImageFromURL('https://www.bostondynamics.com/sites/default/files/styles/max_1300x1300/public/2019-01/MPM_9703-2.jpg?itok=7fe7RDA7');

for (let i = 0; i < robot.width; ++i) {

for (let j = 0; j < robot.height; ++j) {

let c = robot.getPixel(i, j); // get the current RGB index

r_index = c[0]; // get the R index

robot.setPixel(i, j, [r_index, 0.0, 0.0]); // just change the G and B index

}

}

robot.show();

Sorry, I couldn't post any output as I am not sure which JS library you're using please share it in next questions if possible.