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C# Image loses color when saved

I'm working in a little application that will send images to a card printer (Datacard brand), this program should convert the image to only two colors (just like black and white) RGB(217,217,217) and pure white. The problem is that even if in my screen the pictures looks converted, when I save/print the image, it looks black and white.
This method converts the image to black and white so I can later replace only the black color with the RGB 217,217,217
public static Bitmap BitmapTo1Bpp(Bitmap img)
{
int w = img.Width;
int h = img.Height;
Bitmap bmp = new Bitmap(w, h, PixelFormat.Format1bppIndexed);
BitmapData data = bmp.LockBits(new Rectangle(0, 0, w, h),ImageLockMode.ReadWrite, PixelFormat.Format1bppIndexed);
byte[] scan = new byte[(w + 7) / 8];
for (int y = 0; y < h; y++)
{
for (int x = 0; x < w; x++)
{
if (x % 8 == 0) scan[x / 8] = 0;
Color c = img.GetPixel(x, y);
if (c.GetBrightness() >= 0.5) scan[x / 8] |= (byte)(0x80 >> (x % 8));
}
Marshal.Copy(scan, 0, (IntPtr)((long)data.Scan0 + data.Stride * y), scan.Length);
}
bmp.UnlockBits(data);
return bmp;
}
This method replaces the black color for the new one:
public static Image ImageToRGB217_2(Image image)
{
ColorMatrix colorMatrix = new ColorMatrix(new[]
{
new float[] {0.851f, 0.851f, 0.851f, 1.000f, 0.000f},
new float[] {0.851f, 0.851f, 0.851f, 1.000f, 0.000f},
new float[] {0.851f, 0.851f, 0.851f, 1.000f, 0.000f},
new float[] {0.000f, 0.000f, 0.000f, 0.000f, 0.000f},
new float[] {1.000f, 1.000f, 1.000f, 0.000f, 0.000f}
});
Image img = ApplyColorMatrix(image, colorMatrix);
return img;
}
private static Bitmap ApplyColorMatrix(Image sourceImage, ColorMatrix colorMatrix)
{
Bitmap bmp32BppSource = GetArgbCopy(sourceImage);
Bitmap bmp32BppDest = new Bitmap(bmp32BppSource.Width, bmp32BppSource.Height, PixelFormat.Format32bppArgb);
try
{
using (Graphics graphics = Graphics.FromImage(bmp32BppDest))
{
ImageAttributes bmpAttributes = new ImageAttributes();
bmpAttributes.SetColorMatrix(colorMatrix);
graphics.DrawImage(bmp32BppSource, new Rectangle(0, 0, bmp32BppSource.Width, bmp32BppSource.Height),
0, 0, bmp32BppSource.Width, bmp32BppSource.Height, GraphicsUnit.Pixel, bmpAttributes);
}
bmp32BppSource.Dispose();
}
catch (Exception ex)
{
MessageBox.Show(#"Ocurrió un error al intentar aplicar el filtro UV en una de las imágenes, error:" + ex.Message, "Convertidor", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
return bmp32BppDest;
}
private static Bitmap GetArgbCopy(Image sourceImage)
{
Bitmap bmpNew = new Bitmap(sourceImage.Width, sourceImage.Height, PixelFormat.Format32bppArgb);
using (Graphics graphics = Graphics.FromImage(bmpNew))
{
graphics.DrawImage(sourceImage, new Rectangle(0, 0, bmpNew.Width, bmpNew.Height), new Rectangle(0, 0, bmpNew.Width, bmpNew.Height), GraphicsUnit.Pixel);
graphics.Flush();
}
return bmpNew;
}
And here is where I call both:
private void usarFiltroRGB217ToolStripMenuItem_Click(object sender, EventArgs e)
{
pictureBox1.Image = UVImage.ImageToRGB217_2(UVImage.BitmapTo1Bpp((Bitmap)pictureBox1.Image));
pictureBox1.Refresh();
}
This is how the result looks on screen: http://i127.photobucket.com/albums/p128/dawc159951/Preview_zpsxqtzht2a.jpg
But when I save/print, this is what i get:
http://i127.photobucket.com/albums/p128/dawc159951/217_zpsbmuobnrw.png
This is the saving method:
if (saveFileDialog1.ShowDialog() == DialogResult.OK)
{
string path = saveFileDialog1.FileName;
Bitmap tmp = (Bitmap)pictureBox1.Image;
tmp.Save(path, ImageFormat.Bmp);
if (File.Exists(path))
Process.Start(path);
}
I would appreciate any help to find out why i'm not able to get result i need.
Thanks in advance.

Auto crop a rectangle

I want to auto crop the image which I took it from tablet camera. Actually I want to take the picture of id cards and need to auto corp it, I am using black background but sometimes it is too glaze and there is a reflection also, at that time its not cropped properly. Can anyone assist me with c# code to crop the images(Note : I am using phone cameras to take the image of id cards, mostly the background will be black and sometime it will be some other things).
Below I mentioned my code also:
private void ProcessImage(Bitmap bitmap)
{
// lock image
BitmapData bitmapData = bitmap.LockBits(
new Rectangle(0, 0, bitmap.Width, bitmap.Height),
ImageLockMode.ReadWrite, bitmap.PixelFormat);
// step 1 - turn background to black
ColorFiltering colorFilter = new ColorFiltering();
colorFilter.Red = new IntRange(0, 64);
colorFilter.Green = new IntRange(0, 64);
colorFilter.Blue = new IntRange(0, 64);
colorFilter.FillOutsideRange = false;
colorFilter.ApplyInPlace(bitmapData);
// step 2 - locating objects
BlobCounter blobCounter = new BlobCounter();
blobCounter.FilterBlobs = true;
blobCounter.MinHeight = 5;
blobCounter.MinWidth = 5;
blobCounter.ProcessImage(bitmapData);
Blob[] blobs = blobCounter.GetObjectsInformation();
bitmap.UnlockBits(bitmapData);
// step 3 - check objects' type and highlight
SimpleShapeChecker shapeChecker = new SimpleShapeChecker();
Graphics g = Graphics.FromImage(bitmap);
Pen yellowPen = new Pen(Color.Yellow, 2); // circles
Pen redPen = new Pen(Color.Red, 2); // quadrilateral
Pen brownPen = new Pen(Color.Brown, 2); // quadrilateral with known sub-type
Pen greenPen = new Pen(Color.Green, 2); // known triangle
Pen bluePen = new Pen(Color.Blue, 2); // triangle
for (int i = 0, n = blobs.Length; i < n; i++)
{
List<IntPoint> edgePoints = blobCounter.GetBlobsEdgePoints(blobs[i]);
DoublePoint center;
double radius;
List<IntPoint> corners;
// is triangle or quadrilateral
if (shapeChecker.IsConvexPolygon(edgePoints, out corners))
{
// get sub-type
PolygonSubType subType = shapeChecker.CheckPolygonSubType(corners);
Pen pen;
if (subType == PolygonSubType.Rectangle)
{
pen = (corners.Count == 4) ? redPen : bluePen;
}
else
{
pen = (corners.Count == 4) ? brownPen : greenPen;
}
//g.DrawPolygon( pen, ToPointsArray( corners ) );
if (pen.Color.Name == "Red")
{
int intdummy = 0;
g.DrawRectangle(pen, corners[0].X, corners[0].Y, 1150, 750);
//Code for corpping///////
pictureBox2.Image = bitmap;
pictureBox2.SizeMode = PictureBoxSizeMode.StretchImage;
Bitmap croppedBitmap = new Bitmap("E:\\xxx\\Vicas Tablet\\WinImager\\cropimage\\cropimage\\Testing Images\\Image1.jpg");
//croppedBitmap = croppedBitmap.Clone(new Rectangle(corners[0].X, corners[0].Y,1150,750),System.Drawing.Imaging.PixelFormat.DontCare);
croppedBitmap = croppedBitmap.Clone(
new Rectangle(corners[0].X, corners[0].Y, ((int)corners[1].X - (int)corners[0].X), ((int)corners[2].Y - (int)corners[1].Y)), System.Drawing.Imaging.PixelFormat.DontCare);
pictureBox2.Image = croppedBitmap;
////End code for cropping///////////
}
}

Write a word from a string in a different color using g.DrawString()

I use the function below to draw a string on an image. It words great for the most part when I draw a string using one color.
However I want to have a word be in a different color. For example I want to draw "This is a TEST", I want TEST to be red.
What accomplish this using this method?
System.Drawing.Image newImg = new System.Drawing.Bitmap(500, 500);
pictureBox1.Image = TextOverlay(newImg, "This is a TEST", this.Font, Color.Black, ContentAlignment.MiddleCenter, 0.6F);
I'm referring to this line of code and not the OverlayColor parameter:
g.DrawString(OverlayText, f, b, rect, strFormat);
Here is the complete function:
public static Bitmap TextOverlay(Image img, string OverlayText, Font OverlayFont, Color OverlayColor, System.Drawing.ContentAlignment Position, float PercentFill)
{
// create bitmap and graphics used for drawing
// "clone" image but use 24RGB format
Bitmap bmp = new Bitmap(img.Width, img.Height, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
Graphics g = Graphics.FromImage(bmp);
g.DrawImage(img, 0, 0);
int alpha = 255;
// Create the brush based on the color and alpha
SolidBrush b = new SolidBrush(Color.FromArgb(alpha, OverlayColor));
// Measure the text to render (unscaled, unwrapped)
StringFormat strFormat = StringFormat.GenericTypographic;
SizeF s = g.MeasureString(OverlayText, OverlayFont, 100000, strFormat);
// Enlarge font to specified fill (estimated by AREA)
float zoom = (float)(Math.Sqrt(((double)(img.Width * img.Height) * PercentFill) / (double)(s.Width * s.Height)));
FontStyle sty = OverlayFont.Style;
Font f = new Font(OverlayFont.FontFamily, ((float)OverlayFont.Size) * zoom, sty);
int charFit;
int linesFit;
float SQRTFill = (float)(Math.Sqrt(PercentFill));
strFormat.FormatFlags = StringFormatFlags.NoClip; //|| StringFormatFlags.LineLimit || StringFormatFlags.MeasureTrailingSpaces;
strFormat.Trimming = StringTrimming.Word;
SizeF layout = new SizeF(((float)img.Width) * SQRTFill, ((float)img.Height) * 1.5F); // fit to width, allow height to go over
s = g.MeasureString(OverlayText, f, layout, strFormat, out charFit, out linesFit);
// Determine draw area based on placement
RectangleF rect = new RectangleF((bmp.Width - s.Width) / 2F,
(bmp.Height - s.Height) / 2F,
layout.Width,
((float)img.Height) * SQRTFill);
// Add rendering hint (thx to Thomas)
g.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias;
// finally, draw centered text!
g.DrawString(OverlayText, f, b, rect, strFormat);
// clean-up
g.Dispose();
b.Dispose();
f.Dispose();
return bmp;
}

Drawing to a new "layer" in C#

Building a little paint program and am trying to incorporate the concept of layers.
I'm using a PictureBox control to display the image, and getting the Graphics object from the image being displayed by the PictureBox and drawing to that.
My problem is I'm trying to figure out how to draw to a new Graphics object that is overlayed on top of the picture box, and be able to get the newly drawn image without the original image absorbed into the graphic.
If I do something like:
Graphics gr = Graphics.FromImage(myPictureBox.image);
gr.DrawRectangle(blah blah)
...I am editing the original image in the picture box. I want a way to only capture the new stuff being drawn as a separate image, but still have it displayed as an overlay over top of what was already there.
Anyone able to point me in the right direction? Thanks!

I would reckon to use the transparent control and do some modification so it can be used as image layers:
http://www.codeproject.com/Articles/26878/Making-Transparent-Controls-No-Flickering
Probably something like this (make any modification as necessary).
class LayerControl : UserControl
{
private Image image;
private Graphics graphics;
public LayerControl(int width, int height)
{
this.Width = width;
this.Height = height;
image = new Bitmap(width, height);
graphics = Graphics.FromImage(image);
// Set style for control
SetStyle(ControlStyles.OptimizedDoubleBuffer |
ControlStyles.AllPaintingInWmPaint |
ControlStyles.UserPaint, true);
}
// this function will draw your image
protected override void OnPaint(PaintEventArgs e)
{
var bitMap = new Bitmap(image);
// by default the background color for bitmap is white
// you can modify this to follow your image background
// or create a new Property so it can dynamically assigned
bitMap.MakeTransparent(Color.White);
image = bitMap;
Graphics g = e.Graphics;
g.SmoothingMode = SmoothingMode.AntiAlias;
g.PixelOffsetMode = PixelOffsetMode.HighQuality;
g.CompositingQuality = CompositingQuality.GammaCorrected;
float[][] mtxItens = {
new float[] {1,0,0,0,0},
new float[] {0,1,0,0,0},
new float[] {0,0,1,0,0},
new float[] {0,0,0,1,0},
new float[] {0,0,0,0,1}};
ColorMatrix colorMatrix = new ColorMatrix(mtxItens);
ImageAttributes imgAtb = new ImageAttributes();
imgAtb.SetColorMatrix(
colorMatrix,
ColorMatrixFlag.Default,
ColorAdjustType.Bitmap);
g.DrawImage(image,
ClientRectangle,
0.0f,
0.0f,
image.Width,
image.Height,
GraphicsUnit.Pixel,
imgAtb);
}
// this function will grab the background image to the control it self
protected override void OnPaintBackground(PaintEventArgs e)
{
base.OnPaintBackground(e);
Graphics g = e.Graphics;
if (Parent != null)
{
BackColor = Color.Transparent;
int index = Parent.Controls.GetChildIndex(this);
for (int i = Parent.Controls.Count - 1; i > index; i--)
{
Control c = Parent.Controls[i];
if (c.Bounds.IntersectsWith(Bounds) && c.Visible)
{
Bitmap bmp = new Bitmap(c.Width, c.Height, g);
c.DrawToBitmap(bmp, c.ClientRectangle);
g.TranslateTransform(c.Left - Left, c.Top - Top);
g.DrawImageUnscaled(bmp, Point.Empty);
g.TranslateTransform(Left - c.Left, Top - c.Top);
bmp.Dispose();
}
}
}
else
{
g.Clear(Parent.BackColor);
g.FillRectangle(new SolidBrush(Color.FromArgb(255, Color.Transparent)), this.ClientRectangle);
}
}
// simple drawing circle function
public void DrawCircles()
{
using (Brush b = new SolidBrush(Color.Red))
{
using (Pen p = new Pen(Color.Green, 3))
{
this.graphics.DrawEllipse(p, 25, 25, 20, 20);
}
}
}
// simple drawing rectable function
public void DrawRectangle()
{
using (Brush b = new SolidBrush(Color.Red))
{
using (Pen p = new Pen(Color.Red, 3))
{
this.graphics.DrawRectangle(p, 50, 50, 40, 40);
}
}
}
// Layer control image property
public Image Image
{
get
{
return image;
}
set
{
image = value;
// this will make the control to be redrawn
this.Invalidate();
}
}
}
Example how to use it:
LayerControl lc = new LayerControl(100, 100);
lc.Location = new Point(0, 0);
lc.DrawRectangle();
LayerControl lc2 = new LayerControl(100, 100);
lc2.Location = new Point(0, 0);
lc2.DrawCircles();
LayerControl lc3 = new LayerControl(100, 100);
lc3.Location = new Point(0, 0);
lc3.Image = new Bitmap(#"<Image Path>");
// adding control
this.Controls.Add(dc);
this.Controls.Add(dc2);
this.Controls.Add(dc3);
With this method you can have multiple layers that can put overlapping each other (due to the transparency feature it has).
If you want to add it in top of your PictureBox make sure to re-order the control. The Layer Control should be added before your PictureBox control.
// adding control
this.Controls.Clear();
this.Controls.Add(dc);
this.Controls.Add(dc2);
this.Controls.Add(dc3);
this.Controls.Add(PictureBox1);
Hopefully it help.

example code which working fine - take dummy image and layered the original image with custom text
public void LayerImage(System.Drawing.Image Current, int LayerOpacity)
{
Bitmap bitmap = new Bitmap(Current);
int h = bitmap.Height;
int w = bitmap.Width;
Bitmap backg = new Bitmap(w, h + 20);
Graphics g = null;
try
{
g = Graphics.FromImage(backg);
g.Clear(Color.White);
Font font = new Font("Arial", 12, FontStyle.Bold, GraphicsUnit.Pixel);
RectangleF rectf = new RectangleF(70, 90, 90, 50);
Color color = Color.FromArgb(255, 128, 128, 128);
Point atpoint = new Point(backg.Width / 2, backg.Height - 10);
SolidBrush brush = new SolidBrush(color);
StringFormat sf = new StringFormat();
sf.Alignment = StringAlignment.Center;
sf.LineAlignment = StringAlignment.Center;
g.DrawString("BRAND AMBASSADOR", font, brush, atpoint, sf);
g.Dispose();
MemoryStream m = new MemoryStream();
backg.Save(m, System.Drawing.Imaging.ImageFormat.Jpeg);
}
catch { }
Color pixel = new Color();
for (int x = 0; x < bitmap.Width; x++)
{
for (int y = 0; y < bitmap.Height; y++)
{
pixel = bitmap.GetPixel(x, y);
backg.SetPixel(x, y, Color.FromArgb(LayerOpacity, pixel));
}
}
MemoryStream m1 = new MemoryStream();
backg.Save(m1, System.Drawing.Imaging.ImageFormat.Jpeg);
m1.WriteTo(Response.OutputStream);
m1.Dispose();
base.Dispose();
}

Got it working, perhaps I wasn't clear enough in my original question.
Essentially what I ended up doing was storing each layer as a separate Image object, then just hooking into the OnPaint method of my control and manually drawing the graphics in order, instead of just drawing to PictureBox.Image. Works like a charm!

The graphics capabilities of .NET drawing libraries are simple. Their main purpose is direct drawing of GUI. If you want to have layering, alpha transparency or advanced filters, then you should either use 3rd party library or roll your own drawing code.

Lighten/Darken/Transparent part of image

I'm loading up an image into a BitmapImage and convert this into an array of PixelColor's. What I would like is to be able to manipulate some of these pixels to make them Lighter/Darker/Transparent but I can't seem to get it to work. It does work to set it to a certain color but the alpha channel is ignored.
It's a WPF app using C#4
Thanks!
And the code...
namespace BitmapTest {
using System;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Interop;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using Image = System.Windows.Controls.Image;
public partial class MainWindow {
public MainWindow() {
InitializeComponent();
LoadImage();
}
[DllImport("gdi32")]
private static extern int DeleteObject(IntPtr o);
public static BitmapSource LoadBitmap(Bitmap source) {
var ip = source.GetHbitmap();
try {
return Imaging.CreateBitmapSourceFromHBitmap(ip,
IntPtr.Zero, Int32Rect.Empty,
BitmapSizeOptions.FromEmptyOptions());
} finally {
DeleteObject(ip);
}
}
private void LoadImage() {
var i = new Image();
var src = new BitmapImage();
src.BeginInit();
src.UriSource = new Uri("road.jpg", UriKind.Relative);
src.CacheOption = BitmapCacheOption.OnLoad;
src.EndInit();
var pixels = GetPixels(src);
for (var x = 0; x < Math.Min(50, pixels.GetLength(0)); x++) {
for (var y = 0; y < Math.Min(50, pixels.GetLength(1)); y++) {
pixels[x, y] = new PixelColor {Alpha = 100, Red = pixels[x, y].Red, Green = pixels[x, y].Green, Blue = pixels[x, y].Blue};
}
}
var bitmap = new WriteableBitmap(src.PixelWidth, src.PixelHeight, src.DpiX, src.DpiY, src.Format, src.Palette);
PutPixels(bitmap, pixels, 0, 0);
i.Source = bitmap;
i.Stretch = Stretch.Fill;
RootGrid.Children.Add(i);
}
public PixelColor[,] GetPixels(BitmapSource source) {
if (source.Format != PixelFormats.Bgra32)
source = new FormatConvertedBitmap(source, PixelFormats.Bgra32, null, 0);
var pixels = source.CopyPixels();
return pixels;
}
public void PutPixels(WriteableBitmap bitmap, PixelColor[,] pixels, int x, int y) {
var width = pixels.GetLength(0);
var height = pixels.GetLength(1);
var sourceRect = new Int32Rect(0, 0, width, height);
bitmap.WritePixels(sourceRect, pixels, width*4, x, y);
}
[StructLayout(LayoutKind.Sequential)]
public struct PixelColor {
public byte Blue;
public byte Green;
public byte Red;
public byte Alpha;
}
}
public static class BitmapSourceHelper {
public static MainWindow.PixelColor[,] CopyPixels(this BitmapSource source) {
if (source.Format != PixelFormats.Bgra32)
source = new FormatConvertedBitmap(source, PixelFormats.Bgra32, null, 0);
var pixels = new MainWindow.PixelColor[source.PixelWidth, source.PixelHeight];
var stride = source.PixelWidth * ((source.Format.BitsPerPixel + 7) / 8);
var pinnedPixels = GCHandle.Alloc(pixels, GCHandleType.Pinned);
source.CopyPixels(
new Int32Rect(0, 0, source.PixelWidth, source.PixelHeight),
pinnedPixels.AddrOfPinnedObject(),
pixels.GetLength(0) * pixels.GetLength(1) * 4,
stride);
pinnedPixels.Free();
return pixels;
}
}
}

Here is an example of lightening and darkening an image in a windows forms app. The code here is based the Brightness filter section of an article on The Code Project site: Image Processing for Dummies with C# and GDI+ Part 1.
public Bitmap Lighten(Bitmap bitmap, int amount)
{
if (amount < -255 || amount > 255)
return bitmap;
// GDI+ still lies to us - the return format is BGR, NOT RGB.
BitmapData bmData = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
int stride = bmData.Stride;
System.IntPtr Scan0 = bmData.Scan0;
int nVal = 0;
unsafe
{
byte* p = (byte*)(void*)Scan0;
int nOffset = stride - bitmap.Width * 3;
int nWidth = bitmap.Width * 3;
for (int y = 0; y < bitmap.Height; ++y)
{
for (int x = 0; x < nWidth; ++x)
{
nVal = (int)(p[0] + amount);
if (nVal < 0) nVal = 0;
if (nVal > 255) nVal = 255;
p[0] = (byte)nVal;
++p;
}
p += nOffset;
}
}
bitmap.UnlockBits(bmData);
return bitmap;
}
private void btnLighten_Click(object sender, EventArgs e)
{
Bitmap image = pictureBox1.Image as Bitmap;
pictureBox1.Image = Lighten(image, 10);
}
private void btnDarken_Click(object sender, EventArgs e)
{
Bitmap image = pictureBox1.Image as Bitmap;
pictureBox1.Image = Lighten(image, -10);
}

This code would adjusts a given rectangle in the image, according to brightness, contrast, alpha, gamma:
Bitmap clonedImage = originalImage.Clone(rect, originalImage.PixelFormat);
float gamma = 1.0f; // no change in gamma
float adjustedBrightness = brightness - 1.0f;
// create matrix that will brighten and contrast the image
float[][] ptsArray ={
new float[] {contrast, 0, 0, 0, 0}, // scale red
new float[] {0, contrast, 0, 0, 0}, // scale green
new float[] {0, 0, contrast, 0, 0}, // scale blue
new float[] {0, 0, 0, alpha, 0},
new float[] {adjustedBrightness, adjustedBrightness, adjustedBrightness, 0, 1}};
var imageAttributes = new ImageAttributes();
imageAttributes.ClearColorMatrix();
imageAttributes.SetColorMatrix(new ColorMatrix(ptsArray), ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
imageAttributes.SetGamma(gamma, ColorAdjustType.Bitmap);
// Copy back to the original image from the cloned image
Graphics g = Graphics.FromImage(originalImage);
g.DrawImage(clonedImage, new Rectangle(0, 0, clonedImage.Width, clonedImage.Height)
, rect.left, rect.top, rect.Width, rect.Height,
GraphicsUnit.Pixel, imageAttributes);
g.Flush();