---
title: "How to add emboss with Claude (tested prompt and ffmpeg command)"
description: "The whole shot turns flat steel gray, with the bottle, the acrylic block and the creases in the backdrop raised in relief, each outline a bright ridge on one side and a dark shadow on the other. Install one skill and ask Claude Code, or run the ffmpeg command we tested yourself."
url: https://www.recharm.com/effects/emboss
---

# How to add emboss with Claude

The whole shot turns flat steel gray, with the bottle, the acrylic block and the creases in the backdrop raised in relief, each outline a bright ridge on one side and a dark shadow on the other.

Made by the command on this page, from our own test clip.

## Get this effect

1. ### Switch to Code in your [Claude Desktop App](https://claude.com/download)

2. ### Install the skill (once)

   ```
   Install the Recharm video effects skill: download https://recharm-growth-staging.s3.us-east-2.amazonaws.com/website/downloads/recharm-video-effects.zip and unzip it into ~/.claude/skills
   ```

3. ### Ask for the effect

   ```
   Add emboss to input.mp4
   How deep the relief looks: 2
   Brightness of the flat surface, 0-255: 128
   ```

## Several videos, several effects, one ask

Put your clips in the folder, mention them with @, and ask for everything at once. Claude runs one tested script after another on each clip, then joins them.

Add emboss to **@clip1.mp4**, put a sale badge on **@clip2.mp4**, give **@clip3.mp4** a VHS look, then join all three with crossfades.

## Settings you can change

Ask Claude to change any of these, or edit them at the top of the command.

| Setting | Default | What it does                                                      |
| ------- | ------- | ----------------------------------------------------------------- |
| `DEPTH` | `2`     | How deep the relief looks. 1 is subtle, 4 is deeply carved.       |
| `GRAY`  | `128`   | Brightness of the flat surface, 0-255. Lower it for darker metal. |

## Without the skill

Don’t want to install the skill? Paste this prompt into Claude Code and Claude writes the command itself.

```
Apply a gray emboss effect to all of input.mp4, from the first frame to the last. Convert it to grayscale, then run a 3x3 convolution on it with the kernel -2 -2 0 / -2 0 2 / 0 2 2 (rows top to bottom) and add 128 to the result, clipped to 0-255 (ffmpeg: format=gray,convolution=0m='-2 -2 0 -2 0 2 0 2 2':0bias=128). Flat areas become mid-gray (128) and every edge turns into a bright line on one side and a dark line on the other, so the picture looks stamped into metal. No color should remain. Keep the size (540x960), frame rate, length and audio the same. Use ffmpeg and save it as output.mp4.
```

## Run it without Claude

This is the exact command we tested. Save it as `emboss.sh` and run:

```
sh emboss.sh input.mp4 output.mp4
```

```
#!/bin/sh
# Emboss: turn the picture into a gray relief, as if it were stamped into metal.
# Usage: sh emboss.sh input.mp4 output.mp4
set -e
IN="$1"; OUT="$2"
DEPTH=2      # how deep the relief looks (1 is subtle, 4 is deeply carved)
GRAY=128     # the flat surface's brightness (0-255)

# Subtract each pixel's top-left neighbors from its bottom-right ones: every edge gets a bright ridge
# on one side and a dark shadow on the other, and flat areas settle on the GRAY surface.
K="-$DEPTH -$DEPTH 0 -$DEPTH 0 $DEPTH 0 $DEPTH $DEPTH"
ffmpeg -y -i "$IN" -vf "format=gray,convolution=0m='$K':0bias=$GRAY,format=yuv420p" \
  -c:v libx264 -crf 18 -pix_fmt yuv420p -c:a copy "$OUT"
```

## More stylize and art

- [Anime style **Anime style**](https://www.recharm.com/effects/anime-style)
- [ASCII art **ASCII art**](https://www.recharm.com/effects/ascii-art)
- [Blueprint **Blueprint**](https://www.recharm.com/effects/blueprint)
- [Charcoal drawing **Charcoal drawing**](https://www.recharm.com/effects/charcoal-drawing)
- [Claymation style **Claymation style**](https://www.recharm.com/effects/claymation-style)

## Find 3x _winning ads_

Recharm cuts your ad footage into tagged, searchable clips: hooks, testimonials, product shots. Find the shots that win, add the effect with Claude, and ship 3x more ad edits.

[Start 14-day free trial](https://www.recharm.com/get-started)