# 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