Here's the version using System.Drawing (Bitmap) instead of ImageSharp: using System; using System.Drawing; using System.Drawing.Drawing2D; using System.Drawing.Imaging; using System.IO; using System.Threading.Tasks; using Microsoft.AspNetCore.Hosting; using Microsoft.AspNetCore.Http; using Microsoft.AspNetCore.Mvc; namespace YourNamespace.Controllers { public class PhotoController : Controller { private readonly IWebHostEnvironment _hostingEnvironment; public PhotoController(IWebHostEnvironment hostingEnvironment) { _hostingEnvironment = hostingEnvironment; } [HttpPost] public async Task UploadPhoto(IFormFile photo) { if (photo == null || photo.Length == 0) { return BadRequest("No file uploaded."); } var uploadsFolder = Path.Combine(_hostingEnvironment.WebRootPath, "uploads"); if (!Directory.Exists(uploadsFolder)) { Directory.CreateDirectory(uploadsFolder); } var uniqueFileName = Guid.NewGuid().ToString() + Path.GetExtension(photo.FileName); var filePath = Path.Combine(uploadsFolder, uniqueFileName); using (var stream = new MemoryStream()) { await photo.CopyToAsync(stream); using (var originalImage = new Bitmap(stream)) { int size = Math.Min(originalImage.Width, originalImage.Height); int x = (originalImage.Width - size) / 2; int y = (originalImage.Height - size) / 2; using (var squareImage = new Bitmap(size, size)) using (var graphics = Graphics.FromImage(squareImage)) { graphics.CompositingQuality = CompositingQuality.HighQuality; graphics.InterpolationMode = InterpolationMode.HighQualityBicubic; graphics.SmoothingMode = SmoothingMode.HighQuality; graphics.DrawImage(originalImage, new Rectangle(0, 0, size, size), new Rectangle(x, y, size, size), GraphicsUnit.Pixel); squareImage.Save(filePath, GetImageFormat(Path.GetExtension(filePath))); } } } return Ok(new { FileName = uniqueFileName }); } private ImageFormat GetImageFormat(string extension) { switch (extension.ToLower()) { case ".jpg": case ".jpeg": return ImageFormat.Jpeg; case ".png": return ImageFormat.Png; case ".gif": return ImageFormat.Gif; case ".bmp": return ImageFormat.Bmp; default: return ImageFormat.Jpeg; } } } } Note: For .NET Core, you'll need to: 1. Install System.Drawing.Common NuGet package 2. Add this to your project file: netcoreapp3.1 true true