Just need to know the basics of how to load an image  through its pixels, changing them  to create a watermarking pattern of X's. please help :):)

so below are the instructions I have to follow 

Write a program that loads an image and displays only a small part of it (perhaps using a small window, say 400x400). Allow the user to navigate around in the image: if the user moves the mouse pointer to the top of the window, the window should slide up relative to the window until the top of the image is reached, with similar behaviours for the other window sides.

Write pseudocode for a function that takes in an image as argument and converts all the red pixels to blue. Assume that the image has a .data[] or .pixels[] array containing all the individual pixels. (To think about: what is a "red pixel"?)

int[] button = new int[10];
color[] c;

void setup()
{
 size(600,400);
 button = new int[10];
 c = new color[5];
 for (int i = 0; i < 10; i++)
 {
 button[i] = (int)random(5);
 }
 
 c[0] = color(255,0,0);
 c[1] = color(200,100,20);
 c[2] = color(210,200,40);
 c[3] = color(50,250,90);
 c[4] = color(0,0,255);
 
}

void draw()
{
 for (int i = 0; i < 10; i++)
 {
 fill(c[ button[i] ]);
 rect(i*width/10,height/2-50,width/10,100);
 }
}

void mousePressed()
{
 int x = mouseX*10/width;
 if ((mouseY > height/2-50) && (mouseY < height/2+50))
 {
 button[x] = (button[x]+1);
 if (button[x] > 4)
 button[x] = 0;
 }
}

I've been trying to create an array of Strings and fill it with album names, displaying three elements of the array on the screen at a time. as well as i tried to allow the use of key presses  to scroll through the list but that have got me even more lost :S someone please help

 it will return true if the input is prime and false otherwise 

every time i try to create the function it never draws the negative side of the quadratic function 

 write a function that takes an array as the argument and returns the second largest element ?? just get me in the right direction im kinda lost :S

i need to write out a pseudocode for a function called "and" that takes two arguments, both booleans, and returns the logical and of the inputs icant use the logical and operator: instead, write out if statements that cover the possibilities.

Need help I have to write a function that computes the total interest charged on a credit card before it is paid off and list all the inputs the function will need, i don't know where to start and please do not reply in code so i can figure it out myself

int x = 5;

void draw()

{

   changeX();

   print(x);

}

void changeX()

{

   int x = 7;

}

Just wondering how can I simplify my code to reduce the amount of lines ??

Write a program to check whether a car will crash. There is an obstacle at a certain distance (say 100 m) and the car is travelling at a certain speed (try it with some different speeds). The user hits the brakes after 0.5 seconds, applying a deceleration of 5 m/s^2. Draw the progress of the car and report whether it stopped safely or hit the obstacle.

can someone please help me reverse an array

Can someone please guild me step by step (not in code ) on how to write an array im so lost! Here's the question

Write a program to display some data in bar graph form. Have at least 20 elements, which can be positive or negative; draw each element with a vertical bar, going up if the data is positive or down if the data is negative. Once you have displayed the bar graph, allow a user to select a given element by cycling through the data with keys (e.g., 'a' to move left, 's' to move right) and print the exact value of the selected bar. Show the current selection by highlighting its bar somehow (e.g., drawing a thick outline around it).