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How to Resize Center and Crop an image with ImageSharp

I need to convert some System.Drawing based code to use this .NET Core compatible library:
https://github.com/SixLabors/ImageSharp
The System.Drawing based code below resizes an image and crops of the edges, returning the memory stream to then be saved. Is this possible with the ImageSharp library?
private static Stream Resize(Stream inStream, int newWidth, int newHeight)
{
var img = Image.Load(inStream);
if (newWidth != img.Width || newHeight != img.Height)
{
var ratioX = (double)newWidth / img.Width;
var ratioY = (double)newHeight / img.Height;
var ratio = Math.Max(ratioX, ratioY);
var width = (int)(img.Width * ratio);
var height = (int)(img.Height * ratio);
var newImage = new Bitmap(width, height);
Graphics.FromImage(newImage).DrawImage(img, 0, 0, width, height);
img = newImage;
if (img.Width != newWidth || img.Height != newHeight)
{
var startX = (Math.Max(img.Width, newWidth) - Math.Min(img.Width, newWidth)) / 2;
var startY = (Math.Max(img.Height, newHeight) - Math.Min(img.Height, newHeight)) / 2;
img = Crop(img, newWidth, newHeight, startX, startY);
}
}
var ms = new MemoryStream();
img.Save(ms, ImageFormat.Jpeg);
ms.Position = 0;
return ms;
}
private static Image Crop(Image image, int newWidth, int newHeight, int startX = 0, int startY = 0)
{
if (image.Height < newHeight)
newHeight = image.Height;
if (image.Width < newWidth)
newWidth = image.Width;
using (var bmp = new Bitmap(newWidth, newHeight, PixelFormat.Format24bppRgb))
{
bmp.SetResolution(72, 72);
using (var g = Graphics.FromImage(bmp))
{
g.SmoothingMode = SmoothingMode.AntiAlias;
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.PixelOffsetMode = PixelOffsetMode.HighQuality;
g.DrawImage(image, new Rectangle(0, 0, newWidth, newHeight), startX, startY, newWidth, newHeight, GraphicsUnit.Pixel);
var ms = new MemoryStream();
bmp.Save(ms, ImageFormat.Jpeg);
image.Dispose();
var outimage = Image.FromStream(ms);
return outimage;
}
}
}

Yeah, super easy.
using (var inStream = ...)
using (var outStream = new MemoryStream())
using (var image = Image.Load(inStream, out IImageFormat format))
{
image.Mutate(
i => i.Resize(width, height)
.Crop(new Rectangle(x, y, cropWidth, cropHeight)));
image.Save(outStream, format);
}
EDIT
If you want to leave the original image untouched you can use the Clone method instead.
using (var inStream = ...)
using (var outStream = new MemoryStream())
using (var image = Image.Load(inStream, out IImageFormat format))
{
var clone = image.Clone(
i => i.Resize(width, height)
.Crop(new Rectangle(x, y, cropWidth, cropHeight)));
clone.Save(outStream, format);
}
You might even be able to optimize this into a single method call to Resize via the overload that accepts a ResizeOptions instance with `ResizeMode.Crop. That would allow you to resize to a ratio then crop off any excess outside that ratio.

So here's relevent code after so far after converting to not use original methods:
using (var fullSizeStream = new MemoryStream())
using (var smallStream = new MemoryStream())
using (var thumbStream = new MemoryStream())
using (var reviewThumbStream = new MemoryStream())
using (var image = Image.Load(inStream))
{
// Save original constrained
var clone = image.Clone(context => context
.Resize(new ResizeOptions
{
Mode = ResizeMode.Max,
Size = new Size(1280, 1280)
}));
clone.Save(fullSizeStream, new JpegEncoder { Quality = 80 });
//Save three sizes Cropped:
var jpegEncoder = new JpegEncoder { Quality = 75 };
clone = image.Clone(context => context
.Resize(new ResizeOptions
{
Mode = ResizeMode.Crop,
Size = new Size(277, 277)
}));
clone.Save(smallStream, jpegEncoder);
clone = image.Clone(context => context
.Resize(new ResizeOptions
{
Mode = ResizeMode.Crop,
Size = new Size(100, 100)
}));
clone.Save(thumbStream, jpegEncoder);
clone = image.Clone(context => context
.Resize(new ResizeOptions
{
Mode = ResizeMode.Crop,
Size = new Size(50, 50)
}));
clone.Save(reviewThumbStream, jpegEncoder);
//...then I just save the streams to blob storage
}

Using SharpAvi to convert images to video

I'm using SharpAvi .dll to convert a serie of images to video, everything looks fine, but when I try to play the video in windows media player I only get a black screen for one second, nothing else.
This is the code I wrote, (frames is a list of images as base64)
private void CreateMovie(List<string> frames)
{
int width = 320;
int height = 240;
var framRate = 2;
var writer = new AviWriter("C:\\test.avi")
{
FramesPerSecond = framRate,
EmitIndex1 = true
};
var stream = writer.AddVideoStream();
stream.Width = width;
stream.Height = height;
stream.Codec = KnownFourCCs.Codecs.DivX;
stream.BitsPerPixel = BitsPerPixel.Bpp32;
foreach (var frame in frames)
{
byte[] arr = Convert.FromBase64String(frame);
stream.WriteFrame(true, arr, 0, arr.Length);
}
writer.Close();
}
I can't see what the error could be. Does anyone have an idea?

So, i've found the errors:
the line:
stream.Codec = KnownFourCCs.Codecs.DivX;
should be:
stream.Codec = KnownFourCCs.Codecs.Uncompressed;
and all the frames of the video should be the same size as video, in order to do that i've use this block of code:
foreach (var frame in frames)
{
byte[] arr = Convert.FromBase64String(frame);
var bm = ToBitmap(arr);
var rbm = ReduceBitmap(bm, 320, 240);
byte[] fr = BitmapToByteArray(rbm);
stream.WriteFrame(true, fr, 0, fr.Length);
}
and here the helper functions:
public Bitmap ToBitmap(byte[] byteArrayIn)
{
var ms = new MemoryStream(byteArrayIn);
var returnImage = Image.FromStream(ms);
var bitmap = new Bitmap(returnImage);
return bitmap;
}
public Bitmap ReduceBitmap(Bitmap original, int reducedWidth, int reducedHeight)
{
var reduced = new Bitmap(reducedWidth, reducedHeight);
using (var dc = Graphics.FromImage(reduced))
{
dc.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
dc.DrawImage(original, new Rectangle(0, 0, reducedWidth, reducedHeight), new Rectangle(0, 0, original.Width, original.Height), GraphicsUnit.Pixel);
}
return reduced;
}
public static byte[] BitmapToByteArray(Bitmap bitmap)
{
BitmapData bmpdata = null;
try
{
bmpdata = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadOnly, bitmap.PixelFormat);
int numbytes = bmpdata.Stride * bitmap.Height;
byte[] bytedata = new byte[numbytes];
IntPtr ptr = bmpdata.Scan0;
Marshal.Copy(ptr, bytedata, 0, numbytes);
return bytedata;
}
finally
{
if (bmpdata != null)
{
bitmap.UnlockBits(bmpdata);
}
}
}

Image upload quality bad

I have an application that uploads images to a database and then show them in a webpage by using a Handler. My problem is that the images are showing in a different quality and color than the original ones. I don't know what the problem is.
File = FileUpload1.PostedFile;
imgbin = new Byte[File.ContentLength];
File.InputStream.Read(imgbin, 0, File.ContentLength);
imagename = FileUpload1.FileName;
// Here the image size is defined --------------------
System.Drawing.Image UploadedImage = System.Drawing.Image.FromStream(FileUpload1.PostedFile.InputStream);
UploadedImageWidth = UploadedImage.PhysicalDimension.Width;
UploadedImageHeight = UploadedImage.PhysicalDimension.Height;
//Resize Image
int compressWidth;
if (UploadedImageWidth >639)
{
compressWidth = 640;
}
else
{
compressWidth = Convert.ToInt32(UploadedImageWidth);
}
ResizeImage compressPicture = new ResizeImage();
imgbin = compressPicture.ResizeImageFile(imgbin, compressWidth);
System.Drawing.Image Image = System.Drawing.Image.FromStream(new MemoryStream(imgbin));
public class ResizeImage
{
public byte[] ResizeImageFile(byte[] imageFile, int targetSize) // Set targetSize to 1024
{
using (System.Drawing.Image oldImage = System.Drawing.Image.FromStream(new MemoryStream(imageFile)))
{
Size newSize = CalculateDimensions(oldImage.Size, targetSize);
using (Bitmap newImage = new Bitmap(newSize.Width, newSize.Height, PixelFormat.Format64bppPArgb))
{
byte[] byteArray = new byte[0];
using (Graphics canvas = Graphics.FromImage(newImage))
{
canvas.Clear(Color.White);
canvas.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
canvas.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
canvas.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;
canvas.DrawImage(oldImage, new Rectangle(new Point(0, 0), newSize));
int quality = 100;
ImageCodecInfo codec = RetrieveCodec("image/jpeg");
using (MemoryStream m = new MemoryStream())
{
using (EncoderParameters codeParams = new EncoderParameters())
{
using (EncoderParameter p = new EncoderParameter(Encoder.Quality, quality))
{
codeParams.Param[0] = p;
newImage.Save(m, codec, codeParams);
byteArray = m.ToArray();
}
}
}
return byteArray;
}
}
}
}
private ImageCodecInfo RetrieveCodec(string mimeType)
{
ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();
foreach (ImageCodecInfo codec in codecs)
{
if (codec.MimeType == mimeType)
return codec;
}
return null;
}
public static Size CalculateDimensions(Size oldSize, int targetSize)
{
decimal ajusteTamaño;
Size newSize = new Size();
if (oldSize.Width > targetSize)
{
ajusteTamaño = oldSize.Width / Convert.ToDecimal(targetSize);
newSize.Width = (int)(oldSize.Width / ajusteTamaño);
newSize.Height = (int)(oldSize.Height / ajusteTamaño);
}
else
{
newSize.Width = oldSize.Width;
newSize.Height = oldSize.Height;
}
return newSize;
}
}

Image resize without saving on disk

in asp.net i want to resize the image and display on some control but without saving on disk.
is there any free utility just like for clasic asp.
http://www.aspjpeg.com/livedemo.html

This Thumbnail class will do the job.
public class Thumbnail
{
private string _filePath;
private int _maxWidth = 120;
private int _maxHeight = 120;
public string MimeType;
public System.Drawing.Imaging.ImageFormat ImageFormat;
public byte[] ImageBytes;
public Thumbnail(string filePath, int maxWidth, int maxHeight)
{
_filePath = filePath;
_maxWidth = maxWidth;
_maxHeight = maxHeight;
MakeThumbnail();
}
private void MakeThumbnail()
{
using (Image img = new Bitmap(_filePath))
{
Size newSize = GenerateImageDimensions(img.Width, img.Height, _maxWidth, _maxHeight);
int imgWidth = newSize.Width;
int imgHeight = newSize.Height;
// create the thumbnail image
using (Image img2 =
img.GetThumbnailImage(imgWidth, imgHeight,
new Image.GetThumbnailImageAbort(Abort),
IntPtr.Zero))
{
using (Graphics g = Graphics.FromImage(img2)) // Create Graphics object from original Image
{
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
g.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
//BMP 0, JPEG 1 , GIF 2 , TIFF 3, PNG 4
System.Drawing.Imaging.ImageCodecInfo codec;
switch (Path.GetExtension(_filePath))
{
case ".gif":
codec = System.Drawing.Imaging.ImageCodecInfo.GetImageEncoders()[2];
ImageFormat = System.Drawing.Imaging.ImageFormat.Gif;
MimeType = "image/gif";
break;
case ".png":
codec = System.Drawing.Imaging.ImageCodecInfo.GetImageEncoders()[4];
ImageFormat = System.Drawing.Imaging.ImageFormat.Png;
MimeType = "image/png";
break;
default: //jpg
codec = System.Drawing.Imaging.ImageCodecInfo.GetImageEncoders()[1];
ImageFormat = System.Drawing.Imaging.ImageFormat.Jpeg;
MimeType = "image/jpg";
break;
}
//Set the parameters for defining the quality of the thumbnail... here it is set to 100%
System.Drawing.Imaging.EncoderParameters eParams = new System.Drawing.Imaging.EncoderParameters(1);
eParams.Param[0] = new System.Drawing.Imaging.EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 90L);
//Now draw the image on the instance of thumbnail Bitmap object
g.DrawImage(img, new Rectangle(0, 0, img2.Width, img2.Height));
MemoryStream ms = new MemoryStream();
img2.Save(ms, codec, eParams);
ImageBytes = new byte[ms.Length];
ImageBytes = ms.ToArray();
ms.Close();
ms.Dispose();
}
}
}
}
public static Size GenerateImageDimensions(int currW, int currH, int destW, int destH)
{
int imgWidth = currW;
int imgHeight = currH;
if (imgWidth > destW)
{
double rate = (double)imgWidth / (double)destW;
imgWidth = destW;
imgHeight = (int)(imgHeight / rate);
}
if (imgHeight > destH)
{
double rate = (double)imgHeight / (double)destH;
imgHeight = destH;
imgWidth = (int)(imgWidth / rate);
}
return new Size(imgWidth, imgHeight);
}
private bool Abort()
{
return false;
}
}
Using is simple, just put this on your page codebehind. Browser output will be resized image.
Thumbnail thm = new Thumbnail("c:\some_image.jpg", 300, 300);
Response.ContentType = thm.MimeType;
Response.BinaryWrite(thm.ImageBytes);

This is probably what you need:
http://imageresizing.net/

Why does resizing a png image lose transparency?

I am trying to resize an image as follows. I return the resized image into byte[] so that I can store it in database. The transparency of png image is lost. Please help to make this better.
private byte[] GetThumbNail(string imageFile, Stream imageStream,
int imageLen)
{
try
{
Image.GetThumbnailImageAbort imageCallBack =
new Image.GetThumbnailImageAbort(ThumbnailCallback);
Bitmap getBitmap = new Bitmap(imageFile);
byte[] returnByte = new byte[imageLen];
Image getThumbnail = getBitmap.GetThumbnailImage(160, 59,
imageCallBack, IntPtr.Zero);
using (Graphics g = Graphics.FromImage(getThumbnail))
{
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
g.InterpolationMode =
System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
g.DrawImage(getThumbnail, 0, 0, 160, 59);
}
using (MemoryStream ms = new MemoryStream())
{
getThumbnail.Save(ms, ImageFormat.Png);
getThumbnail.Save("test.png", ImageFormat.Png);
returnByte = ms.ToArray();
}
return returnByte;
}
catch (Exception)
{
throw;
}
}

Your code doesn't do quite what you think that it does...
You use the GetThumbnailImage to resize the image, then you draw the thumbnail image into itself which is rather pointless. You probably lose the transparency in the first step.
Create a blank bitmap instead, and resize the source image by drawing it on the blank bitmap.
private byte[] GetThumbNail(string imageFile) {
try {
byte[] result;
using (Image thumbnail = new Bitmap(160, 59)) {
using (Bitmap source = new Bitmap(imageFile)) {
using (Graphics g = Graphics.FromImage(thumbnail)) {
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
g.DrawImage(source, 0, 0, 160, 59);
}
}
using (MemoryStream ms = new MemoryStream()) {
thumbnail.Save(ms, ImageFormat.Png);
thumbnail.Save("test.png", ImageFormat.Png);
result = ms.ToArray();
}
}
return result;
} catch (Exception) {
throw;
}
}
(I removed some parameters that were never used for anything that had anything to do with the result, like the imageLen parameter that was only used to create a byte array that was never used.)

Try using the .MakeTransparent() call on your bitmap object.

May be you should do something like this because this thing worked for me:
String path = context.Server.MapPath("/images");
if (!path.EndsWith("\\"))
path += "\\";
path += "none.png";
Image img = CreateThumbnail(Image.FromFile(path));
MemoryStream ms = new MemoryStream();
img.Save(ms, ImageFormat.Png);
ms.WriteTo(context.Response.OutputStream);
private System.Drawing.Image CreateThumbnail(System.Drawing.Image i)
{
int dWidth = i.Width;
int dHeight = i.Height;
int dMaxSize = 150;
if (dWidth > dMaxSize)
{
dHeight = (dHeight * dMaxSize) / dWidth;
dWidth = dMaxSize;
}
if (dHeight > dMaxSize)
{
dWidth = (dWidth * dMaxSize) / dHeight;
dHeight = dMaxSize;
}
return i.GetThumbnailImage(dWidth, dHeight, delegate() { return false; }, IntPtr.Zero);
}