[OpenCV] Chapter02-02 Converting between different data types and scaling values

Read image from file

Source Code

package main

import (
 "gocv.io/x/gocv"
 "log"
)

func main() {
 imageFilePath := "../../data/Lena.png"
 originalMat := gocv.IMRead(imageFilePath, gocv.IMReadAnyColor)
 if originalMat.Empty() {
  log.Panic("Can not read image: " + imageFilePath)
  return
 }

 // original Image
 log.Println("size:", originalMat.Size())
 log.Println("type:", originalMat.Type()) // MatTypeCV8UC3
 log.Println("channel:", originalMat.Channels())

 windowForOriginal := gocv.NewWindow("Window Original")
 defer windowForOriginal.Close()
 windowForOriginal.IMShow(originalMat)

 // scale Image
 originalImage := originalMat.ToBytes()
 newImage := make([]uint8, len(originalImage))
 for i := 0; i < len(originalImage); i++ {
  clipValue := float32(originalImage[i]) / 255
  if clipValue*2 > 1 {
   newImage[i] = 1
  } else {
   newImage[i] = 0
  }
 }

 for i := 0; i < len(newImage); i++ {
  newImage[i] = newImage[i] * 255
 }

 scaleMat, err := gocv.NewMatFromBytes(originalMat.Rows(), originalMat.Cols(), gocv.MatTypeCV8UC3, newImage)
 if err != nil {
  log.Panic("Can not convert bytes to Mat")
  return
 }

 windowForScale := gocv.NewWindow("Window Scale")
 defer windowForScale.Close()
 windowForScale.IMShow(scaleMat)

 // wait
 for {
  key := gocv.WaitKey(3)
  if key == 27 {
   log.Println("Pressed ESC")
   break
  }
 }
}

Execute Result