Golang image/png processing image rotation writing

package mint

import (
	"github.com/golang/freetype"
	"golang.org/x/image/font"
	"image"
	"image/color"
	"image/draw"
	"image/png"
	"io/ioutil"
	"log"
	"os"
)

func rotate90(m image.Image) image.Image {
	rotate90 := image.NewRGBA(image.Rect(0, 0, m.Bounds().Dy(), m.Bounds().Dx()))
	//  Matrix rotation 
	for x := m.Bounds().Min.Y; x < m.Bounds().Max.Y; x++ {
		for y := m.Bounds().Max.X - 1; y >= m.Bounds().Min.X; y-- {
			//   Set the pixels 
			rotate90.Set(m.Bounds().Max.Y-x, y, m.At(y, x))
		}
	}
	return rotate90
}

//  rotate 180 degree 
func rotate180(m image.Image) image.Image {
	rotate180 := image.NewRGBA(image.Rect(0, 0, m.Bounds().Dx(), m.Bounds().Dy()))
	//  Matrix rotation 
	for x := m.Bounds().Min.X; x < m.Bounds().Max.X; x++ {
		for y := m.Bounds().Min.Y; y < m.Bounds().Max.Y; y++ {
			//   Set the pixels 
			rotate180.Set(m.Bounds().Max.X-x, m.Bounds().Max.Y-y, m.At(x, y))
		}
	}
	return rotate180
}

//  rotate 270 degree 
func rotate270(m image.Image) image.Image {
	rotate270 := image.NewRGBA(image.Rect(0, 0, m.Bounds().Dy(), m.Bounds().Dx()))
	//  Matrix rotation 
	for x := m.Bounds().Min.Y; x < m.Bounds().Max.Y; x++ {
		for y := m.Bounds().Max.X - 1; y >= m.Bounds().Min.X; y-- {
			//  Set the pixels 
			rotate270.Set(x, m.Bounds().Max.X-y, m.At(y, x))
		}
	}
	return rotate270

}
func writeLabel(img image.Image, label string, x, y int, fontColor color.Color, size float64, fontPath string) (image.Image, error) {
	bound := img.Bounds()
	//  Create a new picture 
	rgba := image.NewRGBA(image.Rect(0, 0, bound.Dx(), bound.Dy()))
	//  Read the font 
	fontBytes, err := ioutil.ReadFile(fontPath)
	if err != nil {
		return rgba, err
	}
	myFont, err := freetype.ParseFont(fontBytes)
	if err != nil {
		return rgba, err
	}

	draw.Draw(rgba, rgba.Bounds(), img, bound.Min, draw.Src)
	c := freetype.NewContext()
	c.SetDPI(72)
	c.SetFont(myFont)
	c.SetFontSize(size)
	c.SetClip(rgba.Bounds())
	c.SetDst(rgba)
	uni := image.NewUniform(fontColor)
	c.SetSrc(uni)
	c.SetHinting(font.HintingNone)

	//  Display... In the specified position 
	pt := freetype.Pt(x, y+int(c.PointToFixed(size)>>6))
	if _, err := c.DrawString(label, pt); err != nil {
		return rgba, err
	}

	return rgba, nil
}

func CreatePassImage(cardColor string, createImg string, label string) {
	src, err := os.Open(cardColor)
	if err != nil {
		log.Println(err)
		return
	}
	img, err := png.Decode(src)
	if err != nil {
		log.Println(err)
		return
	}
	image := rotate270(img)
	writeimage, err := writeLabel(image, label, 56, 870, color.RGBA{255, 255, 255, 255}, 60, "./image/PingFang Heavy.ttf")

	if err != nil {
		log.Println(err)
		return
	}
	outimage := rotate90(writeimage)
	f, err := os.Create(createImg)
	if err != nil {
		log.Println(err)
		return
	}
	defer f.Close()

	err = png.Encode(f, outimage)
	if err != nil {
		log.Println(err)
		return
	}
}