---
title: Sharpen
summary: Sharpen specifies options for increasing the definition of the edges of objects in an image.
url: https://www.fastly.com/documentation/reference/compute/sdks/go/compute-sdk-go/fsthttp/imageopto/struct.Sharpen/
---

**Kind:** Struct  
**Module:** [imageopto](https://www.fastly.com/documentation/reference/compute/sdks/go/compute-sdk-go/fsthttp/imageopto/)  
**Package:** compute-sdk-go v1.11.0  
**Source:** https://github.com/fastly/compute-sdk-go/blob/d6bf71b04516ed72d6018cab6fff701a865f86e5/fsthttp/imageopto/imageopto.go#L600

```go
type Sharpen struct {
	Amount uint8

	Radius float32

	Threshold uint8
}
```

Sharpen specifies options for increasing the definition of the edges of objects in an image.

## Fields

### Amount

**Type:** `uint8`

Amount parameter for the unsharp mask.

### Radius

**Type:** `float32`

Radius parameter for the unsharp mask.

### Threshold

**Type:** `uint8`

Threshold parameter for the unsharp mask.

## Methods

### String

**Source:** https://github.com/fastly/compute-sdk-go/blob/d6bf71b04516ed72d6018cab6fff701a865f86e5/fsthttp/imageopto/imageopto.go#L609

```go
func (s *Sharpen) String() string
```

**Returns**

`string`