golang coreml mlmodel & mlpackage inference example using darwinkit

darwinkit_coreml_inference.go

package main

import (
	"github.com/progrium/darwinkit/macos/coreml"
	"github.com/progrium/darwinkit/macos/foundation"
	"github.com/progrium/darwinkit/objc"
	"log"
	"unsafe"
)

func main() {
	// convert with:
	// $ xcrun coremlcompiler compile /path/to/file.mlpackage /outdir/
	// $ xcrun coremlcompiler compile /path/to/file.mlmodel   /outdir/
	modelPath := "/path/to/model.mlmodelc"
	imagePath := "/path/to/image.jpg"

	log.Println("Image path:", imagePath)
	log.Println("Model path:", modelPath)

	// Load the model
	var errModel foundation.Error
	model := coreml.Model_ModelWithContentsOfURLError(
		foundation.URL_FileURLWithPath(modelPath),
		unsafe.Pointer(&errModel),
	)
	if !errModel.IsNil() {
		log.Fatalf(errModel.Description())
	}
	log.Println("Model loaded successfully:", model.ModelDescription())

	// Get the input descriptions, and find the one for "image"
	inputDescriptions := model.ModelDescription().InputDescriptionsByName()
	imageInputDesc := inputDescriptions["image"]
	if imageInputDesc.IsNil() {
		log.Fatalf("Input 'image' not found in model input descriptions")
		return
	}
	imageInputConstraint := imageInputDesc.ImageConstraint()
	log.Println("'image' input constraint:", imageInputConstraint.Description()) //  Color, 640 x 640

	// create features from image
	var errImg foundation.Error
	imageFeature := coreml.FeatureValue_FeatureValueWithImageAtURLConstraintOptionsError(
		foundation.URL_FileURLWithPath(imagePath),
		imageInputConstraint,
		nil,
		unsafe.Pointer(&errImg),
	)
	if !errImg.IsNil() {
		log.Fatalf(errImg.Description())
	}
	log.Println("Image feature created successfully:", imageFeature.Description())

	// predict
	var errFeatures foundation.Error
	featureProvider := coreml.NewDictionaryFeatureProvider()
	featureProvider.InitWithDictionaryError(
		map[string]objc.IObject{"image": imageFeature},
		unsafe.Pointer(&errFeatures),
	)
	if !errFeatures.IsNil() {
		log.Fatalf(errFeatures.Description())
	}
	log.Println("Feature provider created successfully:", featureProvider.Description())
	obj := coreml.FeatureProviderObject{featureProvider.Object}

	// prediction
	var errPred foundation.Error
	result := model.PredictionFromFeaturesError(obj, unsafe.Pointer(&errPred))
	if !errPred.IsNil() {
		log.Fatalf(errPred.Description())
	}
	log.Println("Prediction successful:", result.Description())
}