---
# System prepended metadata

title: Week 4

---

# Week 4

## What if we sum over everything?

### Brightness
Is defined to be greater than 153.

- [ ] Variable
- [x] Constant

```python
MAX_BRIGHTNESS=153
```

```python
main():
max_brightness=153
```

 ### What do we want to do? [narok]
- [x] WORK WITH PIXELS
- [x] Calculate pixel average
- [x] If Bright <- Recognize
    - [x] Then Grayscale
- [x] If not Bright <- Recognize
    - [x] Then Nothing

### About SimpleImage
- Is a collection of Pixel objects
    - Are located by giving x,y pairs
For loop over all pairs of x, then y\

#### Nested For loop
```python
for x in range(0,image.width):
        for y in range(0,image.height):
            print(image.get_pixel(x,y))
```

#### For each
```python
for ix in image:
 print(ix)
```

### Differences
*For our problem as stated above*
- For each iterates over a **collection** of objects
- For iterates over a **range of values**

SimpleImage is a collection of pixel objects
SimpleImage can return pixel **values** with `get_pixel`, given `x` and `y`

## What is our next issue? [trim-crop]
- [x] Pixels
    - [ ] For each
    - [x] For
- [ ] Trimming
- [ ] New Image

- Old image -> 200,100 -> remove 30
- `image.width`-30

### Steps
- Adress the pixels to be removed
- [x] New image
    - [ ] New height
    - [ ] New width

## What is our last issue? [add-border]
- [x] Pixels
- [ ] Padding
- [ ] New Image