> For the complete documentation index, see [llms.txt](https://computational-thinking-in-room11.gitbook.io/room-112-dhs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://computational-thinking-in-room11.gitbook.io/room-112-dhs/cs-in-entertainment/first-down-marker.md).

# First Down Marker

<figure><img src="https://2507214486-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-LpUPSf3tCxHePJxNjfg%2Fuploads%2FTzeNs95jxDB8z83ueg6Z%2Fimage.png?alt=media&amp;token=1082a112-a1b1-454c-bd5b-bdd0d17d145d" alt=""><figcaption></figcaption></figure>

Is this yellow line really on the field?

Are the white lines really on the field?

What about the "ticker" for the score at the bottom of the screen - is it on the actual field?

What is different about the score ticker and that yellow line?

<figure><img src="https://2507214486-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-LpUPSf3tCxHePJxNjfg%2Fuploads%2FGzmgtLJlhBP8kNHZ4Qxx%2Fimage.png?alt=media&amp;token=504df3b1-5491-453a-b5db-9a1150a917f9" alt=""><figcaption></figcaption></figure>

#### Each pixel is a small solid color square arranged in a grid

Today we are going to write the code to scan each pixel on an image

<figure><img src="https://2507214486-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-LpUPSf3tCxHePJxNjfg%2Fuploads%2Fb7xCewxViigemYH8hsd8%2Fimage.png?alt=media&amp;token=05923960-6818-4047-ad17-bf8ec7a0783f" alt=""><figcaption></figcaption></figure>