Pigeon - Google Cloud Vision API on Golang
pigeon is a service for the Google Cloud Vision API on Golang.
Prerequisite
You need to export a service account json file to GOOGLE_APPLICATION_CREDENTIALS variable.
$ export GOOGLE_APPLICATION_CREDENTIALS=/path/to/service_account.json
To generate the credentials file, please, refer to this documentation page
Installation
pigeon provides the command-line tools.
$ go get github.com/kaneshin/pigeon/cmd/...Make sure that pigeon was installed correctly:
$ pigeon -hUsage
pigeon command
pigeon is available to submit request with external image source (i.e. Google Cloud Storage image location).
# Default Detection is LabelDetection.
$ pigeon assets/lenna.jpg
$ pigeon -face gs://bucket_name/lenna.jpg
$ pigeon -label https://httpbin.org/image/jpeg
pigeon package
import "github.com/kaneshin/pigeon"
import "github.com/kaneshin/pigeon/credentials"
func main() {
// Initialize vision service by a credentials json.
creds := credentials.NewApplicationCredentials("credentials.json")
// creds will set a pointer of credentials object using env value of
// "GOOGLE_APPLICATION_CREDENTIALS" if pass empty string to argument.
// creds := credentials.NewApplicationCredentials("")
config := pigeon.NewConfig().WithCredentials(creds)
client, err := pigeon.New(config)
if err != nil {
panic(err)
}
// To call multiple image annotation requests.
feature := pigeon.NewFeature(pigeon.LabelDetection)
batch, err := client.NewBatchAnnotateImageRequest([]string{"lenna.jpg"}, feature)
if err != nil {
panic(err)
}
// Execute the "vision.images.annotate".
res, err := client.ImagesService().Annotate(batch).Do()
if err != nil {
panic(err)
}
// Marshal annotations from responses
body, _ := json.MarshalIndent(res.Responses, "", " ")
fmt.Println(string(body))
}pigeon.Client
The pigeon.Client is wrapper of the vision.Service.
// Initialize vision client by a credentials json.
creds := credentials.NewApplicationCredentials("credentials.json")
client, err := pigeon.New(creds)
if err != nil {
panic(err)
}vision.Feature
vision.Feature will be applied to vision.AnnotateImageRequest.
// DetectionType returns a value of detection type.
func DetectionType(d int) string {
switch d {
case TypeUnspecified:
return "TYPE_UNSPECIFIED"
case FaceDetection:
return "FACE_DETECTION"
case LandmarkDetection:
return "LANDMARK_DETECTION"
case LogoDetection:
return "LOGO_DETECTION"
case LabelDetection:
return "LABEL_DETECTION"
case TextDetection:
return "TEXT_DETECTION"
case SafeSearchDetection:
return "SAFE_SEARCH_DETECTION"
case ImageProperties:
return "IMAGE_PROPERTIES"
}
return ""
}
// Choose detection types
features := []*vision.Feature{
pigeon.NewFeature(pigeon.FaceDetection),
pigeon.NewFeature(pigeon.LabelDetection),
pigeon.NewFeature(pigeon.ImageProperties),
}vision.AnnotateImageRequest
vision.AnnotateImageRequest needs to set the uri of the form "gs://bucket_name/foo.png" or byte content of image.
- Google Cloud Storage
src := "gs://bucket_name/lenna.jpg"
req, err := pigeon.NewAnnotateImageSourceRequest(src, features...)
if err != nil {
panic(err)
}- Base64 Encoded String
b, err := ioutil.ReadFile(filename)
if err != nil {
panic(err)
}
req, err = pigeon.NewAnnotateImageContentRequest(b, features...)
if err != nil {
panic(err)
}Submit the request to the Google Cloud Vision API
// To call multiple image annotation requests.
batch, err := client.NewBatchAnnotateImageRequest(list, features()...)
if err != nil {
panic(err)
}
// Execute the "vision.images.annotate".
res, err := client.ImagesService().Annotate(batch).Do()
if err != nil {
panic(err)
}Example
Pigeon
input
$ pigeon -label assets/pigeon.pngoutput
[
{
"labelAnnotations": [
{
"description": "bird",
"mid": "/m/015p6",
"score": 0.825656
},
{
"description": "anatidae",
"mid": "/m/01c_0l",
"score": 0.58264238
}
]
}
]Lenna
input
$ pigeon -safe-search assets/lenna.jpgoutput
[
{
"safeSearchAnnotation": {
"adult": "POSSIBLE",
"medical": "UNLIKELY",
"spoof": "VERY_UNLIKELY",
"violence": "VERY_UNLIKELY"
}
}
]License
Author
Shintaro Kaneko kaneshin0120@gmail.com
