I'm working on a task that draw a string on an image.
but the result image is not same with source code that I wrote down.
following image shows the font size difference.
red text is written in NanumSquare font 18px in window paint.
and the black text date below red text is also NanumSquare font 18px. It is written with C# source code.
following is my source code. C#.
static void Main(string[] args)
{
DrawTextToImageSave("webPrint_back.png");
}
public static void DrawTextToImageSave(string path)
{
//png to bitmap
Image Dummy = Image.FromFile(path);
using (Bitmap bitmap = (Bitmap)Dummy)
{//load the image file
using (Graphics graphics = Graphics.FromImage(bitmap))
{
graphics.TextRenderingHint = TextRenderingHint.AntiAliasGridFit;
var titleFont = new Font("NanumSquareOTF ExtraBold", 25);
var bodyFont = new Font("NanumSquareOTF Regular", 25);
graphics.DrawString("DATE", titleFont, System.Drawing.Brushes.Black, new PointF(401.5f, 863.5f)); //comment 1
graphics.DrawString(DateTime.Now.ToString("yyyy.MM.dd"), bodyFont, System.Drawing.Brushes.Black, new PointF(345, 885f));
graphics.DrawString("LOCATION", titleFont, System.Drawing.Brushes.Black, new PointF(344, 919.5f));
graphics.DrawString(System.DateTime.Now.ToString("yyyyMMddHHmmss") , bodyFont, System.Drawing.Brushes.Black, new PointF(267f, 946f));
WriteableBitmap bitmapimg = Generator128Code("STACKOVERFLOW", 110, 110);
bitmapimg = resize_image(bitmapimg, 1.4); //comment 2
var stream = new MemoryStream();
var encoder = new JpegBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmapimg));
encoder.Save(stream);
byte[] buffer = stream.GetBuffer();
var qrBitmap = new System.Drawing.Bitmap(new MemoryStream(buffer));
graphics.DrawImage(qrBitmap, 485f, 855f);
}
bitmap.Save( "output_WebPrintBack.png", ImageFormat.Png);
}
}
see comment 1. I expect it draws exactly 18px font. but It does not.
I have also same problem on drawing qrcode with zxing.
without comment2 code I get a ~90 px qr code size.
public static WriteableBitmap Generator128Code(string contents, int width, int height)
{
if (string.IsNullOrEmpty(contents))
{
return null;
}
EncodingOptions options = null;
BarcodeWriter writer = null;
options = new QrCodeEncodingOptions
{
CharacterSet = "UTF-8",
Width = width,
Height = height,
ErrorCorrection = ErrorCorrectionLevel.H,
Margin = 0
};
writer = new BarcodeWriter
{
Format = BarcodeFormat.QR_CODE,
Options = options
};
WriteableBitmap bitmap = writer.Write(contents);
return bitmap;
}
static WriteableBitmap resize_image(WriteableBitmap img, double scale)
{
BitmapSource source = img;
var s = new ScaleTransform(scale, scale);
var res = new TransformedBitmap(img, s);
return convert_BitmapSource_to_WriteableBitmap(res);
}
static WriteableBitmap convert_BitmapSource_to_WriteableBitmap(BitmapSource source)
{
// Calculate stride of source
int stride = source.PixelWidth * (source.Format.BitsPerPixel / 8);
// Create data array to hold source pixel data
byte[] data = new byte[stride * source.PixelHeight];
// Copy source image pixels to the data array
source.CopyPixels(data, stride, 0);
// Create WriteableBitmap to copy the pixel data to.
WriteableBitmap target = new WriteableBitmap(source.PixelWidth
, source.PixelHeight, source.DpiX, source.DpiY
, source.Format, null);
// Write the pixel data to the WriteableBitmap.
target.WritePixels(new Int32Rect(0, 0
, source.PixelWidth, source.PixelHeight)
, data, stride, 0);
return target;
}
with multiplying x 1.4 with its size, I can get similar result that I want.
why this difference has occured?
size of origin image is also 638px * 1010px. following image is origin image.
thank you for reading. and I apologize my poor English skill.
Edit
following source is executable with Console .net framework.
I retry with this source code but the result was same. :( ...
following source code is full source code.
you need png file that named "webPrint_back.png". and size 638x1010 . https://dummyimage.com/
using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Text;
using System.IO;
using System.Windows;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using ZXing;
using ZXing.Common;
using ZXing.QrCode;
using ZXing.QrCode.Internal;
using BarcodeWriter = ZXing.Presentation.BarcodeWriter;
namespace bitmapTest
{
class Program
{
static void Main(string[] args)
{
DrawTextToImageSave("webPrint_back.png");
}
public static void DrawTextToImageSave(string path)
{
//png to bitmap
Image Dummy = Image.FromFile(path);
using (Bitmap bitmap = (Bitmap)Dummy)
{//load the image file
using (Graphics graphics = Graphics.FromImage(bitmap))
{
graphics.TextRenderingHint = TextRenderingHint.AntiAliasGridFit;
var titleFont = new Font("NanumSquareOTF ExtraBold", 18);
var bodyFont = new Font("NanumSquareOTF Regular", 18);
graphics.DrawString("DATE", titleFont, System.Drawing.Brushes.Black, new PointF(401.5f, 863.5f)); //comment 1
graphics.DrawString(DateTime.Now.ToString("yyyy.MM.dd"), bodyFont, System.Drawing.Brushes.Black, new PointF(345, 885f));
graphics.DrawString("LOCATION", titleFont, System.Drawing.Brushes.Black, new PointF(344, 919.5f));
graphics.DrawString(System.DateTime.Now.ToString("yyyyMMddHHmmss") , bodyFont, System.Drawing.Brushes.Black, new PointF(267f, 946f));
WriteableBitmap bitmapimg = Generator128Code("STACKOVERFLOW", 110, 110);
bitmapimg = resize_image(bitmapimg, 1.4); //comment 2
var stream = new MemoryStream();
var encoder = new JpegBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmapimg));
encoder.Save(stream);
byte[] buffer = stream.GetBuffer();
var qrBitmap = new System.Drawing.Bitmap(new MemoryStream(buffer));
graphics.DrawImage(qrBitmap, 485f, 855f);
}
bitmap.Save( "output_WebPrintBack.png", ImageFormat.Png);
}
}
public static WriteableBitmap Generator128Code(string contents, int width, int height)
{
if (string.IsNullOrEmpty(contents))
{
return null;
}
EncodingOptions options = null;
BarcodeWriter writer = null;
options = new QrCodeEncodingOptions
{
CharacterSet = "UTF-8",
Width = width,
Height = height,
ErrorCorrection = ErrorCorrectionLevel.H,
Margin = 0
};
writer = new BarcodeWriter
{
Format = BarcodeFormat.QR_CODE,
Options = options
};
WriteableBitmap bitmap = writer.Write(contents);
return bitmap;
}
static WriteableBitmap resize_image(WriteableBitmap img, double scale)
{
BitmapSource source = img;
var s = new ScaleTransform(scale, scale);
var res = new TransformedBitmap(img, s);
return convert_BitmapSource_to_WriteableBitmap(res);
}
static WriteableBitmap convert_BitmapSource_to_WriteableBitmap(BitmapSource source)
{
// Calculate stride of source
int stride = source.PixelWidth * (source.Format.BitsPerPixel / 8);
// Create data array to hold source pixel data
byte[] data = new byte[stride * source.PixelHeight];
// Copy source image pixels to the data array
source.CopyPixels(data, stride, 0);
// Create WriteableBitmap to copy the pixel data to.
WriteableBitmap target = new WriteableBitmap(source.PixelWidth
, source.PixelHeight, source.DpiX, source.DpiY
, source.Format, null);
// Write the pixel data to the WriteableBitmap.
target.WritePixels(new Int32Rect(0, 0
, source.PixelWidth, source.PixelHeight)
, data, stride, 0);
return target;
}
}
}
I found the factor that makes font size is smaller than I expected.
First, source code that I posted works bad with PNG File with "24 bit depth"(without transparent background).
but PNG file with "32 bit depth"(with transparent background), Fontsize works well.
I don't know why It happened.
Second, the barcode made with zxing.net nuget. internally has padding with its border. the problem is that padding size depends on string length. longer string length makes more smaller barcode size and more bigger padding.
following source is my solution for barcode zxing.net nuget
WriteableBitmap bitmapimg = Generator128Code(StaticCommon.localConfigModel.cardBack_QRText, 110, 110);
var stream = new MemoryStream();
var encoder = new JpegBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmapimg));
encoder.Save(stream);
byte[] buffer = stream.GetBuffer();
var qrBitmap = new System.Drawing.Bitmap(new MemoryStream(buffer));
RectangleF recF = new RectangleF(new PointF(477f, 852f), new SizeF(130, 130));
//ZXING PADDING value, padding size depends on QR encoded string length, so I divide with integer 30 and use remainder
int len = StaticCommon.localConfigModel.cardBack_QRText.Length;
int pad = (int)len / 30;
if (len % 30 > 0) pad++;
RectangleF srecF = new RectangleF(pad * 6f, pad * 6f, 110f - pad * 12f, 110 - pad * 12f);
graphics.DrawImage(qrBitmap, recF, srecF, GraphicsUnit.Pixel);
I solved my problem with engineering way, but I hope someone solve this problem with theoretical way. so I remain this question unsolved.
I recently acquired the NuGet Package Nquant.
I plan to use this to reduce the file size of the bitmap and save it into PNG. But I get this error:
The image you are attempting to quantize does not contain a 32 bit ARGB palette. This image has a bit depth of 8 with 256 colors.
Does anyone here has used Nquant? And have you encountered this error and how did you fix it?
My code for your reference:
var bitmap = new Bitmap(width, jbgsize / height, PixelFormat.Format8bppIndexed);
ColorPalette pal = bitmap.Palette;
for (int i = 0; i <= 255; i++)
{
// create greyscale color table
pal.Entries[i] = Color.FromArgb(i, i, i);
}
bitmap.Palette = pal; // you need to re-set this property to force the new ColorPalette
var bitmap_data = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.WriteOnly, PixelFormat.Format8bppIndexed);
Marshal.Copy(output, 0, bitmap_data.Scan0, output.Length);
bitmap.UnlockBits(bitmap_data);
MemoryStream stream = new MemoryStream();
var quantizer = new WuQuantizer();
using(var bmp = new Bitmap(bitmap))
{
using (var quantized = quantizer.QuantizeImage(bitmap))
{
quantized.Save(stream, ImageFormat.Png);
}
}
byteArray = stream.ToArray();
return byteArray.Concat(output).ToArray();
You can convert your image to Format32bppPArgb and then Quantize it.
This is my working example of that decrease image size for ~3 times.
public static byte[] CompressImageStream(byte[] imageStream)
{
using (var ms = new MemoryStream(imageStream))
using (var original = new Bitmap(ms))
using (var clonedWith32PixelsFormat = new Bitmap(
original.Width,
original.Height,
PixelFormat.Format32bppPArgb))
{
using (Graphics gr = Graphics.FromImage(clonedWith32PixelsFormat))
{
gr.DrawImage(
original,
new Rectangle(0, 0, clonedWith32PixelsFormat.Width, clonedWith32PixelsFormat.Height));
}
using (Image compressedImage = new WuQuantizer().QuantizeImage(clonedWith32PixelsFormat))
{
return ImageToByteArray(compressedImage);
}
}
}
public static byte[] ImageToByteArray(Image image)
{
if (image == null)
{
throw new ArgumentNullException(nameof(image));
}
using (var stream = new MemoryStream())
{
image.Save(stream, ImageFormat.Png);
return stream.ToArray();
}
}
I am trying to convert fingerprint byte array to imagesource in the WPF application but my tricks not working.
Here is the code :
byte[] fp_image; //fp_image contains the fingerprint byte array result
using (MemoryStream ms = new MemoryStream(fp_image))
{
Bitmap bmp = new Bitmap(ms);
FpImage.Source = ConvertToImageSource(bmp);
}
public static ImageSource ConvertToImageSource(Bitmap bitmap)
{
var imageSourceConverter = new ImageSourceConverter();
using (var memoryStream = new MemoryStream())
{
bitmap.Save(memoryStream, ImageFormat.Png);
var snapshotBytes = memoryStream.ToArray();
return (ImageSource)imageSourceConverter.ConvertFrom(snapshotBytes); ;
}
}
Note : If I convert any other image to byte array and convert it back to image with this code it's working.
Assuming byte[] fp_image contains raw data then you could directly create a BitmapSource (which is a subclass of ImageSource) with the method shown below. However, you need to know the width, height and pixel format of the bitmap in your buffer.
public BitmapSource GetBitmapFromRawBytes(
byte[] rawBytes, int width, int height, PixelFormat format)
{
var stride = (width * format.BitsPerPixel + 7) / 8;
return BitmapSource.Create(width, height, 96, 96, format, null, rawBytes, stride);
}
I´m using Kinect (Microsoft SDK) with XNA. I want to use GRATF for marker-recognition
How to convert the data of a Kinect ColorImageFrame to a System.Drawing.Bitmap or AForge.Imaging.UnmanagedImage that I can process them with GRATF?
void kinectSensor_ColorFrameReady(object sender, ColorImageFrameReadyEventArgs e)
{
Bitmap bitmap = null;
ColorImageFrame frame = e.OpenColorImageFrame();
byte[] buffer = new byte[frame.PixelDataLength];
frame.CopyPixelData(buffer);
// how to convert the data in buffer to a bitmap?
var glyphs = recognizer.FindGlyphs(bitmap);
...
}
You can find the answer in this article.
To summarize it, this method should do the trick:
Bitmap ImageToBitmap(ColorImageFrame img)
{
byte[] pixeldata = new byte[img.PixelDataLength];
img.CopyPixelDataTo(pixeldata);
Bitmap bmap = new Bitmap(img.Width, img.Height, PixelFormat.Format32bppRgb);
BitmapData bmapdata = bmap.LockBits(
new Rectangle(0, 0, img.Width, img.Height),
ImageLockMode.WriteOnly,
bmap.PixelFormat);
IntPtr ptr = bmapdata.Scan0;
Marshal.Copy(pixeldata, 0, ptr, img.PixelDataLength);
bmap.UnlockBits(bmapdata);
return bmap;
}
The XAML:
<ImageBrush x:Key="Symbol1Brush" ImageSource="Resources\Symbol1.png" Stretch="Uniform" />
The code:
// In some class
_imageProcessor = new ImageProcessor(Resources["Symbol1Image"] as BitmapImage)
and
public class ImageProcessor
{
private readonly Bitmap _primaryMarkerSymbol;
public ImageProcessor(BitmapImage primaryMarkerSymbol)
{
if (primaryMarkerSymbol == null)
throw new ArgumentNullException("primaryMarkerSymbol");
_primaryMarkerSymbol = new Bitmap(primaryMarkerSymbol.StreamSource);
}
public Bitmap ProcessImage()
{
Graphics g = Graphics.FromImage(img);
g.DrawImage(_primaryMarkerSymbol);
g.Flush();
return img;
}
}
_primaryMarkerSymbol = new Bitmap(primaryMarkerSymbol.StreamSource)
throws Exception: Value of 'null' is not valid for 'stream'.
I assume the StreamSource is not populated if BitmapImage is created from Resource.
What alternatives there are?
Thanks.
EDIT:
The point is to use the source object (ex. ImageBrush, BitmapImage) defined in the XAML ResourceDictionary.
You might need to copy the bitmap's pixels somehow like this:
// test image
BitmapImage image = new BitmapImage(new Uri(#"C:\Users\Public\Pictures\Sample Pictures\Desert.jpg"));
// copy to byte array
int stride = image.PixelWidth * 4;
byte[] buffer = new byte[stride * image.PixelHeight];
image.CopyPixels(buffer, stride, 0);
// create bitmap
System.Drawing.Bitmap bitmap =
new System.Drawing.Bitmap(
image.PixelWidth,
image.PixelHeight,
System.Drawing.Imaging.PixelFormat.Format32bppArgb);
// lock bitmap data
System.Drawing.Imaging.BitmapData bitmapData =
bitmap.LockBits(
new System.Drawing.Rectangle(0, 0, bitmap.Width, bitmap.Height),
System.Drawing.Imaging.ImageLockMode.WriteOnly,
bitmap.PixelFormat);
// copy byte array to bitmap data
System.Runtime.InteropServices.Marshal.Copy(
buffer, 0, bitmapData.Scan0, buffer.Length);
// unlock
bitmap.UnlockBits(bitmapData);
This worked for me to set an image source using resource files
var bitmapSource = Imaging.CreateBitmapSourceFromHBitmap(MyProject.Properties.Resources.myImage.GetHbitmap(),
IntPtr.Zero,
Int32Rect.Empty,
BitmapSizeOptions.FromEmptyOptions());
MyButton.Background = new ImageBrush(bitmapSource);
In the constructor, I would rather use this:
System.Windows.Resources.StreamResourceInfo imageInfo = System.Windows.Application.GetResourceStream(primaryMarkerSymbol.UriSource);
_primaryMarkerSymbol = Image.FromStream(imageInfo.Stream);
On a clear moment I have come up with a solution that I could saddle with.
I used the BitmapImage.UriSource to get the relative image path and load the Image:
public class ImageProcessor
{
private readonly Image _primaryMarkerSymbol;
public ImageProcessor(BitmapImage primaryMarkerSymbol)
{
_primaryMarkerSymbol = Image.FromFile(primaryMarkerSymbol.UriSource.ToString());
}
public Bitmap ProcessImage(string fileName)
{
var img = new Bitmap(fileName);
Graphics g = Graphics.FromImage(img);
g.DrawImage(_primaryMarkerSymbol);
g.Flush();
return img;
}
}
It would be good if I could use the object itself to draw the image on the graphics not to load by path. So you are welcome to come up with a better idea.