An open API service indexing awesome lists of open source software.

https://github.com/mdouchement/hdr

HDR is a library that handles RAW image format written with Golang
https://github.com/mdouchement/hdr

drago golang golang-library hdr hdr-image hdri icam raw reinhard tmo tone-mapping

Last synced: 9 months ago
JSON representation

HDR is a library that handles RAW image format written with Golang

Awesome Lists containing this project

README

          

# HDR - High Dynamic Range

[![GoDoc](https://img.shields.io/badge/godoc-reference-blue.svg)](https://godoc.org/github.com/mdouchement/hdr)
[![Go Report Card](https://goreportcard.com/badge/github.com/mdouchement/hdr)](https://goreportcard.com/report/github.com/mdouchement/hdr)
[![License](https://img.shields.io/github/license/mdouchement/hdr.svg)](http://opensource.org/licenses/MIT)

HDR is a library that handles RAW image format written with Golang. [Here](https://github.com/mdouchement/hdr_examples#hdr-gallery-examples) some rendering examples.

It aims to provide tools to read [HDR](https://en.wikipedia.org/wiki/High-dynamic-range_imaging) files and convert it to a LDR (Low Dynamic Range, aka PNG/JPEG/etc.) in an `image.Image` object.

Documentations:
- http://www.anyhere.com/gward/hdrenc/hdr_encodings.html

## Supported codecs (file formats)

- Radiance RGBE/XYZE
- PFM, Portable FloatMap file format
- TIFF using [mdouchement/tiff](https://github.com/mdouchement/tiff)
- CRAD, homemade HDR file format

## Supported tone mapping operators

Read this [documentation](http://osp.wikidot.com/parameters-for-photographers) to find what TMO use.

Read this [documentation](https://hal.archives-ouvertes.fr/hal-00724931/document) to understand what is a TMO.

- Linear
- Logarithmic
- Drago '03 - Adaptive logarithmic mapping for displaying high contrast scenes
- Durand - Fast bilateral filtering for the display of high-dynamic-range images
- Reinhard '05 - Photographic tone reproduction for digital images
- Playing with parameters could provide better rendering
- Custom Reinhard '05
- Rendering looks like a JPEG photo taken with a smartphone
- iCAM06 - A refined image appearance model for HDR image rendering

## Usage

```sh
go get github.com/mdouchement/hdr
```

```go
package main

import (
"fmt"
"image"
"image/png"
"os"
"runtime"
"time"

"github.com/mdouchement/hdr"
_ "github.com/mdouchement/hdr/codec/rgbe"
"github.com/mdouchement/hdr/tmo"
)

// Samples:
//
// http://www.anyhere.com/gward/hdrenc/pages/originals.html
// http://resources.mpi-inf.mpg.de/tmo/logmap/ (High Contrast Scenes)

var (
// input = "/Users/mdouchement/tmp/hdr/memorial_o876.hdr"
// input = "/Users/mdouchement/tmp/hdr/MtTamWest_o281.hdr"
// input = "/Users/mdouchement/tmp/hdr/rend02_oC95.hdr"
// input = "/Users/mdouchement/tmp/hdr/Tree_oAC1.hdr"
input = "/Users/mdouchement/tmp/hdr/Apartment_float_o15C.hdr"
output = "/Users/mdouchement/tmp/hdr/output.png"
)

func main() {
fmt.Printf("Using %d CPUs\n", runtime.NumCPU())

fi, err := os.Open(input)
check(err)
defer fi.Close()

start := time.Now()

m, fname, err := image.Decode(fi)
check(err)

fmt.Printf("Read image (%s) took %v\n", fname, time.Since(start))

if hdrm, ok := m.(hdr.Image); ok {
startTMO := time.Now()

// t := tmo.NewLinear(hdrm)
// t := tmo.NewLogarithmic(hdrm)
// t := tmo.NewDefaultDrago03(hdrm)
// t := tmo.NewDefaultDurand(hdrm)
// t := tmo.NewDefaultCustomReinhard05(hdrm)
t := tmo.NewDefaultReinhard05(hdrm)
// t := tmo.NewDefaultICam06(hdrm)
m = t.Perform()

fmt.Println("Apply TMO took", time.Since(startTMO))
}

fo, err := os.Create(output)
check(err)

png.Encode(fo, m)

fmt.Println("Total", time.Since(start))
}

func check(err error) {
if err != nil {
panic(err)
}
}
```

## HDR Tools

[https://github.com/mdouchement/hdrtool](https://github.com/mdouchement/hdrtool)

## License

**MIT**

## Implementing a TMO

A TMO must implement `tmo.ToneMappingOperator`:

```go
type ToneMappingOperator interface {
// Perform runs the TMO mapping.
Perform() image.Image
}
```

## Implementing an image codec

- Reader

```go
// DecodeConfig returns the color model and dimensions of a PFM image without
// decoding the entire image.
func DecodeConfig(r io.Reader) (image.Config, error) {
// ...
return m, err
}

// Decode reads a HDR image from r and returns an image.Image.
func Decode(r io.Reader) (img image.Image, err error) {
// ...
return
}

func init() {
// Register the format in the official lib.
// https://golang.org/pkg/image/#RegisterFormat
image.RegisterFormat("format-name", "magic-code", Decode, DecodeConfig)
}
```

- Writer

```go
// Encode writes the Image m to w in PFM format.
func Encode(w io.Writer, m hdr.Image) error {
return nil
}
```

## Contributing

All PRs are welcome. If you implement a TMO or an image codec in a dedicated repository, please tell me in order to link it in this readme.

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
5. Push to the branch (git push origin my-new-feature)
6. Create new Pull Request

As possible, run the following commands to format and lint the code:

```sh
# Format
find . -name '*.go' -not -path './vendor*' -exec gofmt -s -w {} \;

# Lint
golangci-lint run -c .golangci.yml
```