https://github.com/mamantoha/crystal-exif
Crystal bindings for libexif
https://github.com/mamantoha/crystal-exif
bindings crystal exif libexif
Last synced: 12 months ago
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Crystal bindings for libexif
- Host: GitHub
- URL: https://github.com/mamantoha/crystal-exif
- Owner: mamantoha
- License: mit
- Created: 2022-04-22T08:37:53.000Z (almost 4 years ago)
- Default Branch: main
- Last Pushed: 2022-09-19T08:30:35.000Z (over 3 years ago)
- Last Synced: 2025-02-09T20:16:26.207Z (about 1 year ago)
- Topics: bindings, crystal, exif, libexif
- Language: Crystal
- Homepage: https://mamantoha.github.io/crystal-exif/
- Size: 358 KB
- Stars: 2
- Watchers: 3
- Forks: 0
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# Exif
[](https://github.com/mamantoha/crystal-exif/actions/workflows/crystal.yml)
[](https://github.com/mamantoha/crystal-exif/releases)
[](https://mamantoha.github.io/crystal-exif/)
[](https://github.com/mamantoha/crystal-exif/blob/master/LICENSE)
Crystal C bindings for libexif.
Provides basic support for reading EXIF tags on files using libexif and Crystal.
## Installation
Get libexif for your OS:
```
# MacOS
brew install libexif
# Debian/Ubuntu
apt-get install -y libexif-dev
# RedHat/Fedora
dnf install -y libexif-devel
```
Add the dependency to your `shard.yml`:
```yaml
dependencies:
exif:
github: mamantoha/crystal-exif
```
Run `shards install`
## Usage
This is an example on how to read EXIF data from a file:
```crystal
require "exif"
```
The image is taken from [exif-samples](https://github.com/ianare/exif-samples) repository.
### Load EXIF data from a JPEG file
```crystal
file = File.open("metadata_test.jpg")
exif = Exif.new(file)
exif.data
```
```crystal
{"compression" => "JPEG compression",
"image_description" => "",
"make" => "NIKON",
"model" => "COOLPIX P6000",
"orientation" => "Top-left",
"x_resolution" => "300",
"y_resolution" => "300",
"resolution_unit" => "Inch",
"software" => "Nikon Transfer 1.1 W",
"date_time" => "2008:11:01 21:15:07",
"ycbcr_positioning" => "Centered",
"exposure_time" => "1/75 sec.",
"fnumber" => "f/5.9",
"exposure_program" => "Normal program",
"iso_speed_ratings" => "64",
"exif_version" => "Exif Version 2.2",
"date_time_original" => "2008:10:22 16:28:39",
"date_time_digitized" => "2008:10:22 16:28:39",
"components_configuration" => "Y Cb Cr -",
"exposure_bias_value" => "0.00 EV",
"max_aperture_value" => "2.90 EV (f/2.7)",
"metering_mode" => "Pattern",
"light_source" => "Unknown",
"flash" => "Flash did not fire, compulsory flash mode",
"focal_length" => "24.0 mm",
"maker_note" => "3298 bytes undefined data",
"user_comment" => "",
"flash_pix_version" => "FlashPix Version 1.0",
"color_space" => "sRGB",
"pixel_x_dimension" => "640",
"pixel_y_dimension" => "480",
"file_source" => "DSC",
"scene_type" => "Directly photographed",
"custom_rendered" => "Normal process",
"exposure_mode" => "Auto exposure",
"white_balance" => "Auto white balance",
"digital_zoom_ratio" => "0.00",
"focal_length_in35_mm_film" => "112",
"scene_capture_type" => "Standard",
"gain_control" => "Normal",
"contrast" => "Normal",
"saturation" => "Normal",
"sharpness" => "Normal",
"subject_distance_range" => "Unknown",
"gps_latitude_ref" => "N",
"gps_latitude" => "43, 28, 2.81400000",
"gps_longitude_ref" => "E",
"gps_longitude" => "11, 53, 6.45599999",
"gp_altitude_ref" => "Sea level",
"gps_time_stamp" => "14:27:07.24",
"gps_satellites" => "06",
"gps_img_direction_ref" => "",
"gps_map_datum" => "WGS-84",
"gps_date_stamp" => "2008:10:23"}
```
### Return an Exif entry for the given tag
```crystal
file = File.open("metadata_test.jpg")
exif = Exif.new(file)
exif.make # => "NIKON"
exif.model # => "COOLPIX P6000"
```
### Return the MakerNote data out of the EXIF data
```crystal
file = File.open("metadata_test.jpg")
exif = Exif.new(file)
exif.mnote_data
```
```crystal
{"Firmware" => "0210",
"ISO" => "ISO 0",
"ColorMode1" => "COLOR",
"Quality" => "FINE",
"WhiteBalance" => "AUTO",
"Sharpening" => "NORMAL",
"FocusMode" => "AF-S",
"FlashSetting" => "",
"ISOSelection" => "AUTO",
"FaceDetect" => "8 bytes unknown data: 01004001f0000000",
"ActiveDLighting" => "0",
"ImageAdjustment" => "NORMAL",
"ToneCompensation" => "NORMAL",
"Adapter" => "OFF",
"DigitalZoom" => "1.000",
"AFFocusPosition" => "AF position: center",
"ShotInfo" => "18 bytes unknown data: 000000000e00000000000000000044430000",
"Saturation" => "0",
"NoiseReduction," => "OFF",
"RetouchHistory" => "Invalid number of components (6, expected 1).",
"Saturation2" => "NORMAL",
"CaptureEditorVer" => "COOLPIX P6000V1.0"}
```
## Development
```
crystal ./lib/crystal_lib/src/main.cr src/exif/lib_exif.cr.in > src/exif/lib_exif.cr
```
## Contributing
1. Fork it ()
2. Create your feature branch (`git checkout -b my-new-feature`)
3. Commit your changes (`git commit -am 'Add some feature'`)
4. Push to the branch (`git push origin my-new-feature`)
5. Create a new Pull Request
## Contributors
- [Anton Maminov](https://github.com/mamantoha) - creator and maintainer