I have a method which saves the image from a panel. This method is using Bitmap class. I wants that my method should return byte array of the image.
private byte[] SaveImage()
{
byte[] byteContent = null;
using (Bitmap bitmap = new Bitmap(500, 500))
{
using (Graphics g = Graphics.FromImage(bitmap))
{
Rectangle rectangle = myPanel.Bounds;
Point sourcePoints = myPanel.PointToScreen(new Point(myPanel.ClientRectangle.X, myPanel.ClientRectangle.Y));
g.CopyFromScreen(sourcePoints, Point.Empty, rectangle.Size);
}
string fileName = #"E:\\MyImages.Jpg";
bitmap.Save(fileName, System.Drawing.Imaging.ImageFormat.Jpeg);
}
return byteContent;
}
You'll need to use a MemoryStream to serialize the bitmap to an image format and get the bytes;
using (Bitmap bitmap = new Bitmap(500, 500))
{
using (Graphics g = Graphics.FromImage(bitmap))
{
...
}
using (var memoryStream = new MemoryStream())
{
bitmap.Save(memoryStream, System.Drawing.Imaging.ImageFormat.Jpeg);
return memoryStream.ToArray();
}
}
There are multiple output formats to choose from, you may instead want Bmp or MemoryBmp.
Related
I had Converted Jpg to Webp But I want to resize the image.
using (Bitmap bitmap = new Bitmap(UploadName +jpgFileName))
{
using (var saveImageStream = System.IO.File.Open(webpFileName, FileMode.Create))
{
var encoder = new SimpleEncoder();
encoder.Encode(bitmap, saveImageStream, 90);
}
}
I think you can first resize in jpg then you convert from jpg to webp.
those methods i use to resize image:
You can recive a IFormFile jpgImage and convert to byte[] using method below:
public byte[] GetBytes(IFormFile formFile)
{
using var fileStream = formFile.OpenReadStream();
var bytes = new byte[formFile.Length];
fileStream.Read(bytes, 0, (int)formFile.Length);
return bytes;
}
// Methods to resize the jpg image in byte[]
using SixLabors.ImageSharp;
using SixLabors.ImageSharp.PixelFormats;
using SixLabors.ImageSharp.Processing;
...
public byte[] ResizeImage(byte[] img, int width, int height)
{
using var image = SixLabors.ImageSharp.Image.Load(img);
var options = new ResizeOptions
{
Size = new Size(width, height),
Mode = ResizeMode.Max
};
return Resize(image, options);
}
private byte[] Resize(Image<Rgba32> image, ResizeOptions resizeOptions)
{
byte[] ret;
image.Mutate(i => i.Resize(resizeOptions));
using MemoryStream ms = new MemoryStream();
image.SaveAsJpeg(ms);
ret = ms.ToArray();
ms.Close();
return ret;
}
After resize the jpg image in byte[] you convert to webp
The last line of the following code gives the error "Parameter is not valid", when the original image is an SVG:
var imageBytes = Convert.FromBase64String(imageBase64String);
var memStream = new MemoryStream(imageBytes);
//memStream.Seek(0, SeekOrigin.Begin);
var imageObject = new Bitmap(memStream);
Help please. Thanks.
EDIT: The image for example I am using is the image of the first formula in the following page right under the Theoremsection:
https://en.wikipedia.org/wiki/Green%27s_theorem
Can you try with 'using' for memorystream to handle garbage collection by itself?
var imageBytes = Convert.FromBase64String(imageBase64String);
Bitmap m = ByteToBitmap(imageBytes);
public static Bitmap ByteToBitmap(byte[] imageByte)
{
using (MemoryStream mStream = new MemoryStream())
{
mStream.Write(imageByte, 0, imageByte.Length); // this will stream dataand handle image length by itself
mStream.Seek(0, SeekOrigin.Begin);
Bitmap bm = new Bitmap(mStream);
return bm;
}
}
For SVG,
public static Bitmap ByteToBitmap(byte[] imageByte)
{
using (MemoryStream mStream = new MemoryStream(imageByte))
{
var s= SvgDocument.Open(mStream);
var bm= svgDocument.Draw();
return bm;
}
}
I have a code in form1 constructor:
ConvertedBmp = ConvertTo24(newest.FullName);
The function ConvertTo24 is:
private static Bitmap ConvertTo24(string inputFileName)
{
sw = Stopwatch.StartNew();
Bitmap bmpIn = (Bitmap)Bitmap.FromFile(inputFileName);
Bitmap converted = new Bitmap(bmpIn.Width, bmpIn.Height, PixelFormat.Format24bppRgb);
using (Graphics g = Graphics.FromImage(converted))
{
g.PageUnit = GraphicsUnit.Pixel;
g.DrawImageUnscaled(bmpIn, 0, 0);
}
sw.Stop();
return converted;
}
The problem is how can i use the ConvertedBmp in this line:
backTexture = TextureLoader.FromFile(D3Ddev, #"D:\test.bmp");
TextureLoader have some properties and two of them are: Fromfile and it's getting device and string or FromStream and it's getting device and Stream.
I have the device object already but how can i use the ConvertedBmp(Bitmap type) with the TextureLoader ?
Bitmap class has a method called Save() which accepts a Stream (for example a MemoryStream object) and an ImageFormat, use that. After saved the Bitmap into a MemoryStream you can use that with TextureLoader.
Image.Save Method (Stream, ImageFormat)
I get below code from here:
http://www.java2s.com/example/csharp/system.drawing/bitmap-to-memory-stream.html
public static MemoryStream ToMemoryStream(this Bitmap b)
{
MemoryStream ms = new MemoryStream();
b.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
return ms;
}
Work for my need
I was looking for a routine by which I can crop tiff image and I got it but it gives many error. Here is the routine:
Bitmap comments = null;
string input = "somepath";
// Open a Stream and decode a TIFF image
using (Stream imageStreamSource = new FileStream(input, FileMode.Open, FileAccess.Read, FileShare.Read))
{
TiffBitmapDecoder decoder = new TiffBitmapDecoder(imageStreamSource, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.Default);
BitmapSource bitmapSource = decoder.Frames[0];
using (Bitmap b = BitmapFromSource(bitmapSource))
{
Rectangle cropRect = new Rectangle(169, 1092, 567, 200);
comments = new Bitmap(cropRect.Width, cropRect.Height);
//first cropping
using (Graphics g = Graphics.FromImage(comments))
{
g.DrawImage(b, new Rectangle(0, 0, comments.Width, comments.Height),
cropRect,
GraphicsUnit.Pixel);
}
}
}
When I try to compile it, I get an error. I tried adding references to many assemblies searching google but couldn't resolve it. I got this code from this url:
http://snipplr.com/view/63053/
I am looking for advice.
TiffBitmapDecoder class is from Presentation.Core in another words it is from WPF.
BitmapFromSource isn't method of any .net framework class. You can convert BitmapSource to Bitmap using this code.
private Bitmap BitmapFromSource(BitmapSource bitmapsource)
{
Bitmap bitmap;
using (MemoryStream outStream = new MemoryStream())
{
BitmapEncoder encoder = new BmpBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmapsource));
encoder.Save(outStream);
bitmap = new Bitmap(outStream);
}
return bitmap;
}
I created a function to allow uploaded transparent .png files to be inserted into a SQL Server database and the displayed on a web page via an HttpHandler.
While this all works, the png transparency changes to black when it's viewed on the web page. Is there a way of preserving the transparency?
Here's my image service which inserts into the database from the MVC controller:
public void AddImage(int productId, string caption, byte[] bytesOriginal)
{
string jpgpattern = ".jpg|.JPG";
string pngpattern = ".png|.PNG";
string pattern = jpgpattern;
ImageFormat imgFormat = ImageFormat.Jpeg;
if (caption.ToLower().EndsWith(".png"))
{
imgFormat = ImageFormat.Png;
pattern = pngpattern;
}
ProductImage productImage = new ProductImage();
productImage.ProductId = productId;
productImage.BytesOriginal = bytesOriginal;
productImage.BytesFull = Helpers.ResizeImageFile(bytesOriginal, 600, imgFormat);
productImage.BytesPoster = Helpers.ResizeImageFile(bytesOriginal, 198, imgFormat);
productImage.BytesThumb = Helpers.ResizeImageFile(bytesOriginal, 100, imgFormat);
productImage.Caption = Common.RegexReplace(caption, pattern, "");
productImageDao.Insert(productImage);
}
And here's the "ResizeImageFile" helper function:
public static byte[] ResizeImageFile(byte[] imageFile, int targetSize, ImageFormat imageFormat)
{
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.Format24bppRgb))
{
using (Graphics canvas = Graphics.FromImage(newImage))
{
canvas.SmoothingMode = SmoothingMode.AntiAlias;
canvas.InterpolationMode = InterpolationMode.HighQualityBicubic;
canvas.PixelOffsetMode = PixelOffsetMode.HighQuality;
canvas.DrawImage(oldImage, new Rectangle(new Point(0, 0), newSize));
MemoryStream m = new MemoryStream();
newImage.Save(m, imageFormat);
return m.GetBuffer();
}
}
}
}
What do I need to do to preserve the png transparency? Please show examples. I'm seriously not an expert with image manipulation.
Thanks.
Maybe try changing pixel format form PixelFormat.Format24bppRgb to PixelFormat.Format32bppRgb. You need the extra 8 bits to hold the alpha channel.
Using PixelFormat.Format32bppRgb didn't work for me. What worked however is using oldImage.PixelFormat when drawing the new image. So the corresponding line of code becomes:
using (Bitmap newImage = new Bitmap(newSize.Width, newSize.Height, oldImage.PixelFormat))