NGraphics converting SVG to PNG does not scale the image properly - c#

I have svg icon that I am trying to convert to PNG. I am trying to make the PNG 100x100 pixels, but instead of scaling the image to this size, it gets cropped. What I am doing wrong?
using (StreamReader reader = File.OpenText(svgpath))
{
SvgReader svgReader = new SvgReader(reader);
Graphic gr = svgReader.Graphic;
Size size = new Size(100, 100);
var c = PlatformSupport.CreateImageCanvas(size);
gr.Draw(c);
MemoryStream stream = new MemoryStream();
c.GetImage().SaveAsPng(stream);
byte[] fileContent = stream.ToArray();
File.WriteAllBytes(resultPath, fileContent);
}

Related

how to display image in picturebox without saving in local file system in C#?

//Retrieve an image in Jpg format and store it into a variable.
var imgFile = (ImageFile)ScanerItem.Transfer(FormatID.wiaFormatJPEG);
var Path = #"D:\ScanImg.jpg";
// save the image in some path with filename.
imgFile.SaveFile(Path);
pictureBox1.ImageLocation = Path;
Based on the following SO answer, you can get the byte[] of the image with (byte[])imgFile.FileData.get_BinaryData():
converting .__comobj WIA to byte[] in C# application
A bitmap can be put as source into the PictureBox.
Therefore the byte[] as to put into a MemoryStream and create a Bitmap:
var imgFile = (ImageFile)ScanerItem.Transfer(FormatID.wiaFormatJPEG);
byte[] imageBytes = (byte[])imgFile.FileData.get_BinaryData();
Bitmap image;
using (MemoryStream stream = new MemoryStream(imageBytes))
{
image = new Bitmap(stream);
}
pictureBox1.Image = image;

How can I convert high resolution JPG to byte array?

I have a 63572 x 63573 High resolution JPG image.
I want to convert the image to byte array and convert byte array to OpenCvsharp.Mat.
the image is grayscale.
I tried to way that below code. However, It occurs 'System.OverflowException'(System.Drawing.dll).
System.Drawing.Image image = System.Drawing.Image.FromFile(filepath);
MemoryStream ms = new MemoryStream();
image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
var data = ms.ToArray();
So, I tried to way that below code. However,
It didn't run properly.
var data = File.ReadAllBytes(filepath);
using (Mat mat = new Mat(height, width, MatType.CV_8UC1, data))
{
...
}

How to insert a dynamically generated bitmap into PDF document using PDFsharp?

I am trying to use PDFsharp to insert a dynamically generated bitmap of a QR Code in to a PDF document. I don't want to save the bitmap to the file but just want to insert it into the PDF. The problem I'm having is the DrawImage command is looking for a string where the image file is located. But I don't want to save the file, I just want to insert it into the PDF document. Is there a way of doing this?
var QRCode_BMP = _generalCode.QR_CodeGenerator(AddReviewPath); //This generates the bitmap
MemoryStream streamQR = new MemoryStream();
QRCode_BMP.Save(streamQR, System.Drawing.Imaging.ImageFormat.Jpeg); //save bitmap into memory stream in jpeg format System.Drawing.Image QR_Jpeg = System.Drawing.Image.FromStream(streamQR);// save memory stream to image file
XImage xImage = XImage.FromGdiPlusImage(QR_Jpeg);
gfx = XGraphics.FromPdfPage(page);
DrawImage(gfx, xImage, 0, 0, 100, 100); //This is not working
QRCode_BMP.Dispose();
streamQR.Close();
gfx.Dispose();
You create a QR code in QRCode_BMP and then you create an XImage from QR_Jpeg and write it is not working.
QRCode_BMP is only used to create a stream that is never used. We don't see where QR_Jpeg is coming from.
Provide a complete sample.
BTW: You can use XImage.FromStream to use the stream you created.
P.S.: IMHO JPEG is a bad choice for QR codes. Just use BMP and PDFsharp will use a lossless compression.
This is how I made it work;
PdfDocument pdf = PdfGenerator.GeneratePdf("<b>some html here</b>", PageSize.A4);
QRCodeGenerator qrGenerator = new QRCodeGenerator();
QRCodeData qrCodeData = qrGenerator.CreateQrCode("some text here", QRCodeGenerator.ECCLevel.Q);
QRCode qrCode = new QRCode(qrCodeData);
Bitmap qrCodeImage = qrCode.GetGraphic(10);
PdfPage page = pdf.Pages[0]; //I will add it to 1st page
// Get an XGraphics object for drawing
XGraphics gfx = XGraphics.FromPdfPage(page);
XImage image = XImage.FromGdiPlusImage(qrCodeImage); //you can use XImage.FromGdiPlusImage to get the bitmap object as image (not a stream)
gfx.DrawImage(image, 50, 50, 150, 150);
//save your pdf, dispose other objects
Using XImage.FromStream like #I liked the old Stack Overflow mentioned, in your posted code you should be able to just use:
var QRCode_BMP = _generalCode.QR_CodeGenerator(AddReviewPath); //This generates the bitmap
MemoryStream streamQR = new MemoryStream();
QRCode_BMP.Save(streamQR, System.Drawing.Imaging.ImageFormat.Jpeg); //save bitmap into memory stream in jpeg format System.Drawing.Image QR_Jpeg = System.Drawing.Image.FromStream(streamQR);// save memory stream to image file
//XImage xImage = XImage.FromGdiPlusImage(QR_Jpeg); // <-- Removed
gfx = XGraphics.FromPdfPage(page);
gfx.DrawImage(XImage.FromStream(streamQR), 0, 0, 100, 100); // <-- Added
//DrawImage(gfx, xImage, 0, 0, 100, 100); //This is not working // <-- Removed
QRCode_BMP.Dispose();
streamQR.Close();
gfx.Dispose();
For general usage of streams for XGraphics.DrawImage (library PDFSharp) here's some code I use to print SVG vector path data to PDF:
System.Windows.Shapes.Path path = new System.Windows.Shapes.Path();
// YouTube like button SVG vector path data:
path.Data = Geometry.Parse("M12.42,14A1.54,1.54,0,0,0,14,12.87l1-4.24C15.12,7.76,15,7,14,7H10l1.48-3.54A1.17,1.17,0,0,0,10.24,2a1.49,1.49,0,0,0-1.08.46L5,7H1v7ZM9.89,3.14A.48.48,0,0,1,10.24,3a.29.29,0,0,1,.23.09S9,6.61,9,6.61L8.46,8H14c0,.08-1,4.65-1,4.65a.58.58,0,0,1-.58.35H6V7.39ZM2,8H5v5H2Z");
// Visual check of the path:
// https://yqnn.github.io/svg-path-editor/
// Color area bordered through path of SVG vector:
path.Fill = new SolidColorBrush(Colors.Black);
// Upscale path, if final image is blurry:
double scale = 2;
path.RenderTransform = new ScaleTransform(scale, scale);
Rect bounds = path.Data.GetRenderBounds(null);
// Increase render bounds (here: "+ 4"), if parts of the path in the final image are cut off (test it with "scale = 1" before upscaling):
bounds.Width = (bounds.Width + 4) * scale;
bounds.Height = (bounds.Height + 4) * scale;
path.Measure(bounds.Size);
path.Arrange(bounds);
RenderTargetBitmap bitmap = new RenderTargetBitmap(
(int)bounds.Width, (int)bounds.Height, 96, 96, PixelFormats.Pbgra32);
bitmap.Render(path);
// Transparent areas are replaced with black pixels when using a "BmpBitmapEncoder", so instead use a "PngBitmapEncoder":
PngBitmapEncoder encoderPng = new PngBitmapEncoder();
encoderPng.Frames.Add(BitmapFrame.Create(bitmap));
using (MemoryStream stream = new MemoryStream())
{
encoderPng.Save(stream);
// Draw image to PDF using "XGraphics.DrawImage":
gfx.DrawImage(XImage.FromStream(stream), 10, 100, 14.05, 12.05);
}

Image compression is not working

I have an operation on the site that takes crops an image, however the resultant, cropped image is coming out significantly larger in terms of file size (original is 24k and the cropped image is like 650k). So I found that I need to apply some compression to the image before saving it. I came up with the following:
public static System.Drawing.Image CropImage(System.Drawing.Image image, Rectangle cropRectangle, ImageFormat format)
{
var croppedImage = new Bitmap(cropRectangle.Width, cropRectangle.Height);
using (var g = Graphics.FromImage(croppedImage))
{
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.DrawImage(
image,
new Rectangle(new Point(0,0), new Size(cropRectangle.Width, cropRectangle.Height)),
cropRectangle,
GraphicsUnit.Pixel);
return CompressImage(croppedImage, format);
}
}
public static System.Drawing.Image CompressImage(System.Drawing.Image image, ImageFormat imageFormat)
{
var bmp = new Bitmap(image);
var codecInfo = EncoderFactory.GetEncoderInfo(imageFormat);
var encoder = System.Drawing.Imaging.Encoder.Quality;
var parameters = new EncoderParameters(1);
var parameter = new EncoderParameter(encoder, 10L);
parameters.Param[0] = parameter;
using (var ms = new MemoryStream())
{
bmp.Save(ms, codecInfo, parameters);
var resultImage = System.Drawing.Image.FromStream(ms);
return resultImage;
}
}
I set the quality low just to see if there was any change at all. There isn't. The crop is being saved correctly appearance-wise but compression is a no joy. If I bypass CompressImage() altogether, neither the file size nor the image quality appear to be any different.
So, 2 questions. Why is nothing happening? Is there a simpler way to compress the resultant image to "web-optimize" similar to how photoshop saves web images (I thought it just stripped a lot of info out of it to reduce the size).
Your problem is you must 'compress' (really encode) the image as you save it, not before you save it. An Image object in your program is always uncompressed.
By saving to the MemoryStream and reading back out from the stream will encode the image and then decode it back to the same size again (with some quality loss in the process if you are using JPEG). However, if you save it to a file with the compression parameters, you will get a compressed image file.
Using this routine with JPEG quality level 90 on a 153 KB source image gives an output image of 102 KB. If you want a smaller file size (with more encoding artifacts) change the encoder parameter to something smaller than 90.
public static void SaveJpegImage(System.Drawing.Image image, string fileName)
{
ImageCodecInfo codecInfo = ImageCodecInfo.GetImageEncoders()
.Where(r => r.CodecName.ToUpperInvariant().Contains("JPEG"))
.Select(r => r).FirstOrDefault();
var encoder = System.Drawing.Imaging.Encoder.Quality;
var parameters = new EncoderParameters(1);
var parameter = new EncoderParameter(encoder, 90L);
parameters.Param[0] = parameter;
using (FileStream fs = new FileStream(fileName, FileMode.Create))
{
image.Save(fs, codecInfo, parameters);
}
}
I believe you shouldn't dispose of the MemoryStream while you are using an image created using Image.FromStream that refers to the stream. Creating a Bitmap directly from the stream also doesn't work.
Try this:
private static Image CropAndCompressImage(Image image, Rectangle rectangle, ImageFormat imageFormat)
{
using(Bitmap bitmap = new Bitmap(image))
{
using(Bitmap cropped = bitmap.Clone(rectangle, bitmap.PixelFormat))
{
using (MemoryStream memoryStream = new MemoryStream())
{
cropped.Save(memoryStream, imageFormat);
return new Bitmap(Image.FromStream(memoryStream));
}
}
}
}

convert binary to bitmap using memory stream

Hi I wanna convert binary array to bitmap and show image in a picturebox. I wrote the following code but I got exception that says that the parameter is not valid .
public static Bitmap ByteToImage(byte[] blob)
{
MemoryStream mStream = new MemoryStream();
byte[] pData = blob;
mStream.Write(pData, 0, Convert.ToInt32(pData.Length));
Bitmap bm = new Bitmap(mStream);
mStream.Dispose();
return bm;
}
It really depends on what is in blob. Is it a valid bitmap format (like PNG, BMP, GIF, etc?). If it is raw byte information about the pixels in the bitmap, you can not do it like that.
It may help to rewind the stream to the beginning using mStream.Seek(0, SeekOrigin.Begin) before the line Bitmap bm = new Bitmap(mStream);.
public static Bitmap ByteToImage(byte[] blob)
{
using (MemoryStream mStream = new MemoryStream())
{
mStream.Write(blob, 0, blob.Length);
mStream.Seek(0, SeekOrigin.Begin);
Bitmap bm = new Bitmap(mStream);
return bm;
}
}
Don't dispose of the MemoryStream. It now belongs to the image object and will be disposed when you dispose the image.
Also consider doing it like this
var ms = new MemoryStream(blob);
var img = Image.FromStream(ms);
.....
img.Dispose(); //once you are done with the image.
System.IO.MemoryStream mStrm = new System.IO.MemoryStream(your byte array);
Image im = Image.FromStream(mStrm);
im.Save("image.bmp");
Try this. If you still get any error or exception; please post your bytes which you are trying to convert to image. There should be problem in your image stream....

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