# Brand New the Processing - Need help!
**URL:** https://discourse.processing.org/t/brand-new-the-processing-need-help/43286
**Category:** Beginners
**Tags:** homework
**Created:** [November 22, 2023, 9:12pm UTC](https://discourse.processing.org/t/brand-new-the-processing-need-help/43286 "2023-11-22T21:12:32Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@Amamallama](https://discourse.processing.org/u/Amamallama)
#### Post date: [November 22, 2023, 9:12pm UTC](https://discourse.processing.org/t/brand-new-the-processing-need-help/43286/1 "2023-11-22T21:12:32Z")
```auto
PImage img;
void setup() {
size(1000, 1000);
img = loadImage( "rickroll.jpg" );
}
void draw() {
loadPixels();
img.loadPixels();
for (int x = 0; x < img.width; x++ ) {
for (int y = 0; y < img.height; y++ ) {
int loc = x + y*img.width;
float r = red (img.pixels[loc]);
float g = green(img.pixels[loc]);
float b = blue (img.pixels[loc]);
float distance = dist(x, y, mouseX, mouseY);
float adjustBrightness = map(distance, 0, 50, 8, 0);
r *= adjustBrightness;
g *= adjustBrightness;
b *= adjustBrightness;
r = constrain(r, 0, 255);
g = constrain(g, 0, 255);
b = constrain(b, 0, 255);
color c = color(r, g, b);
pixels[loc] = c;
}
}
updatePixels();
}
```
The file rickroll.jpg is in the right place, but Processing says that
ArrayIndexOutOfBoundsException: Index 40600 out of bounds for length 40000
for this line: pixels[loc] = c;
I know this is beginner stuff. My brain is just having the hardest time right now. Can you help?
---
### Author:  [@GoToLoop](https://discourse.processing.org/u/GoToLoop)
#### Post date: [November 22, 2023, 9:30pm UTC](https://discourse.processing.org/t/brand-new-the-processing-need-help/43286/2 "2023-11-22T21:30:09Z")
> [@Amamallama](#):
>
> `size(1000, 1000);`
> [@Amamallama](#):
>
> `int loc = x + y*img.width;`
> [@Amamallama](#):
>
> `pixels[loc] = c;`
How do you know your “rickroll.jpg” is 1000 x 1000?
---
### Author:  [@Amamallama](https://discourse.processing.org/u/Amamallama)
#### Post date: [November 22, 2023, 9:31pm UTC](https://discourse.processing.org/t/brand-new-the-processing-need-help/43286/3 "2023-11-22T21:31:10Z")
Yeah, ive no idea what size it is. 🤦♀️
---
### Author:  [@Amamallama](https://discourse.processing.org/u/Amamallama)
#### Post date: [November 22, 2023, 9:31pm UTC](https://discourse.processing.org/t/brand-new-the-processing-need-help/43286/4 "2023-11-22T21:31:58Z")
How do I find that out?
---
### Author:  [@GoToLoop](https://discourse.processing.org/u/GoToLoop)
#### Post date: [November 22, 2023, 9:51pm UTC](https://discourse.processing.org/t/brand-new-the-processing-need-help/43286/5 "2023-11-22T21:51:23Z")
A more streamlined approach is to make canvas’ **size()** match the image’s _width_ & _height_ dimensions inside callback **settings()**:
> **[settings() / Reference](https://processing.org/reference/settings_.html)**
>
> The settings() function is new with Processing 3.0. It's not needed in most sketches. It's only useful when it's absolutely necessary to define the parameters to size() with a variable. …
```auto
static final String IMAGE_FILENAME = "rickroll.jpg";
PImage img;
void settings() {
img = loadImage(IMAGE_FILENAME);
size(img.width, img.height);
}
```
---
### Author:  [@Amamallama](https://discourse.processing.org/u/Amamallama)
#### Post date: [November 22, 2023, 10:22pm UTC](https://discourse.processing.org/t/brand-new-the-processing-need-help/43286/6 "2023-11-22T22:22:38Z")
Hmm. Where does the settings callback go? I am not sure how that works.
---
### Author:  [@Chrisir](https://discourse.processing.org/u/Chrisir)
#### Post date: [November 23, 2023, 3:38am UTC](https://discourse.processing.org/t/brand-new-the-processing-need-help/43286/7 "2023-11-23T03:38:09Z")
Just place it before setup ()
Delete size command in setup () maybe
---
### Author:  [@Chrisir](https://discourse.processing.org/u/Chrisir)
#### Post date: [November 23, 2023, 3:42am UTC](https://discourse.processing.org/t/brand-new-the-processing-need-help/43286/8 "2023-11-23T03:42:41Z")
Check [settings() / Reference / Processing.org](https://processing.org/reference/settings_.html)