Is there any open source library for drawing text to image in C#? I have been strugling with TextRenderer and graphics.DrawString() whole day but I never got close to getting decent results, I tried every combination of Smoothing, Interpolation, TextRenderHint but quality is always semi-decent.
Here are some images and that is best I achived:
How it needs to look like:
This really looks good but with some strings seems like character spacing is wrong with some letters and the string leans.
Settings are:
objGraphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
objGraphics.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAliasGridFit;
objGraphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.GammaCorrected;
objGraphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
objGraphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.Half;
objGraphics.TextContrast = 0;
Format is Png and background is transparent, method is TextRenderer.Drawtext(). Seems like thickness of text is wrong, I assume it's something wrong with smoothing, when I try to bold text it stays almost the same, but only with font size of ~10px.
Here's what I use to add a Copyright watermark to photos uploaded to my website:
//Add Watermark to photo.
private System.Drawing.Image CreateWatermark(System.Drawing.Image imgPhoto, string Copyright)
{
Graphics g = Graphics.FromImage(imgPhoto);
g.SmoothingMode = SmoothingMode.HighQuality;
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.PixelOffsetMode = PixelOffsetMode.HighQuality;
foreach (PropertyItem pItem in imgPhoto.PropertyItems)
{
imgPhoto.SetPropertyItem(pItem);
}
int phWidth = imgPhoto.Width;
int phHeight = imgPhoto.Height;
//create a Bitmap the Size of the original photograph
Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
//load the Bitmap into a Graphics object
Graphics grPhoto = Graphics.FromImage(bmPhoto);
//------------------------------------------------------------
//Step #1 - Insert Copyright message
//------------------------------------------------------------
//Set the rendering quality for this Graphics object
grPhoto.SmoothingMode = SmoothingMode.AntiAlias;
//Draws the photo Image object at original size to the graphics object.
grPhoto.DrawImage(
imgPhoto, // Photo Image object
new Rectangle(0, 0, phWidth, phHeight), // Rectangle structure
0, // x-coordinate of the portion of the source image to draw.
0, // y-coordinate of the portion of the source image to draw.
phWidth, // Width of the portion of the source image to draw.
phHeight, // Height of the portion of the source image to draw.
GraphicsUnit.Pixel); // Units of measure
//-------------------------------------------------------
//to maximize the size of the Copyright message we will
//test multiple Font sizes to determine the largest posible
//font we can use for the width of the Photograph
//define an array of point sizes you would like to consider as possiblities
//-------------------------------------------------------
int[] sizes = new int[] { 16, 14, 12, 10, 8, 6, 4 };
Font crFont = null;
SizeF crSize = new SizeF();
//Loop through the defined sizes checking the length of the Copyright string
//If its length in pixles is less then the image width choose this Font size.
for (int i = 0; i < 7; i++)
{
//set a Font object to Arial (i)pt, Bold
crFont = new Font("arial", sizes[i], FontStyle.Bold);
//Measure the Copyright string in this Font
crSize = grPhoto.MeasureString(Copyright, crFont);
if ((ushort)crSize.Width < (ushort)phWidth)
break;
}
//Since all photographs will have varying heights, determine a
//position 5% from the bottom of the image
int yPixlesFromBottom = (int)(phHeight * .05);
//Now that we have a point size use the Copyrights string height
//to determine a y-coordinate to draw the string of the photograph
float yPosFromBottom = ((phHeight - yPixlesFromBottom) - (crSize.Height / 2));
//Determine its x-coordinate by calculating the center of the width of the image
float xCenterOfImg = (phWidth / 2);
//Define the text layout by setting the text alignment to centered
StringFormat StrFormat = new StringFormat();
StrFormat.Alignment = StringAlignment.Near;
//define a Brush which is semi trasparent black (Alpha set to 153)
SolidBrush semiTransBrush2 = new SolidBrush(System.Drawing.Color.FromArgb(153, 0, 0, 0));
//Draw the Copyright string
grPhoto.DrawString(Copyright, //string of text
crFont, //font
semiTransBrush2, //Brush
new PointF(xCenterOfImg + 1, yPosFromBottom + 1), //Position
StrFormat);
//define a Brush which is semi trasparent white (Alpha set to 153)
SolidBrush semiTransBrush = new SolidBrush(System.Drawing.Color.FromArgb(153, 255, 255, 255));
//Draw the Copyright string a second time to create a shadow effect
//Make sure to move this text 1 pixel to the right and down 1 pixel
grPhoto.DrawString(Copyright, //string of text
crFont, //font
semiTransBrush, //Brush
new PointF(xCenterOfImg, yPosFromBottom), //Position
StrFormat); //Text alignment
imgPhoto = bmPhoto;
return imgPhoto;
}
Using System.Drawing classes in ASP.NET is not supported.
Specifically, if you use it, under load from multiple threads, you will experience exceptions like this one:
Win32Exception: The operation completed successfully
at MS.Win32.HwndWrapper..ctor(Int32 classStyle, Int32 style, Int32 exStyle, Int32 x, Int32 y, Int32 width, Int32 height, String name, IntPtr parent, HwndWrapperHook[] hooks)
at System.Windows.Media.MediaContextNotificationWindow..ctor(MediaContext ownerMediaContext)
at System.Windows.Media.MediaContext..ctor(Dispatcher dispatcher)
That said, we discovered that marshaling all drawing operations to a single STA thread seemed to avoid these issues.
UPDATE: It's been five years and we still have no problem with this approach.
Related
Im drawing Text using the following code onto a Bitmap
GraphicsPath pth = new GraphicsPath();
var style = (int)myfont.Style;
pth.AddString(tcaption.Text, myfont.FontFamily, style, myfont.Size, point, StringFormat.GenericTypographic);
p = new Pen(new SolidBrush(bc), 2f);
mygraphics.DrawPath(p, pth);
I'm using the TextRenderer to measure the size of the string..
int Width = TextRenderer.MeasureText(tcaption.Text, myfont).Width;
But this does not produce the correct size of the drawn string; there is around 20-30% difference from the actual size of the drawn string?
What im i doing wrong? Please advice.
UPDATE:
I want to draw a Text and an Image onto a Bitmap,so inorder to accommodate both i'm creating an Bitmap like this
intWidth = TextRenderer.MeasureText(tcaption.Text, cfont).Width + image.Width;
intHeight = TextRenderer.MeasureText(tcaption.Text, cfont).Height +image.Height;
tempimage= new Bitmap(intWidth, intHeight);
Then i create Graphics object from the Bitmap like this
using (Graphics newg = Graphics.FromImage(tempimage))
#Hans Passant
I have also tried the Graphics.MeasureString as an alternative to TextRenderer
Now i set the position of the text and image-I need to draw the image at the top left corner .. so
imageposy = 0;
imageposx = 10;
textposy = image.Height;
textposx = 0;
Then i draw the text like this
po=new Point(textposx, textposy);
newg.SmoothingMode = SmoothingMode.AntiAlias;
GraphicsPath pth = new GraphicsPath();
var style = (int)myfont.Style;
pth.AddString(tcaption.Text, myfont.FontFamily, style, myfont.Size, po,
StringFormat.GenericTypographic);
newg.FillPath(new SolidBrush(fc), pth);
Now i draw the image like this
Rectangle nrect = new Rectangle(imageposx, imageposy, image.Width,
image.Height);
objGraphics = Graphics.FromImage(tempimage);
objGraphics.DrawImage(image, nrect);
As you have seen i need to add the offset 10 to imageposition x coordinate to correct the measurement issue.
Hope my update throws more light into the question... what im i doing wrong?
Please advice..
instead of using TextRenderer use GraphicsPath:
var path = new GraphicsPath();
path.AddString(text, font.FontFamily, (int)font.Style, size, new Point(0, 0), StringFormat.GenericTypographic);
var area = Rectangle.Round(path.GetBounds());
Here is sample code that generates image with size of text:
private Image DrawText(String text, Font font, int size, Color textColor, Color backColor)
{
var path = new GraphicsPath();
path.AddString(text, font.FontFamily, (int)font.Style, size, new Point(0, 0), StringFormat.GenericTypographic);
var area = Rectangle.Round(path.GetBounds());
Rectangle br = Rectangle.Round(path.GetBounds());
var img = new Bitmap(br.Width, br.Height);
var drawing = Graphics.FromImage(img);
drawing.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAliasGridFit;
drawing.SmoothingMode = SmoothingMode.HighSpeed;
drawing.Clear(backColor);
drawing.TranslateTransform((img.Width - br.Width) / 2 - br.X, (img.Height - br.Height) / 2 - br.Y);
drawing.FillPath(Brushes.Black, path);
Brush textBrush = new SolidBrush(textColor);
drawing.Save();
textBrush.Dispose();
drawing.Dispose();
return img;
}
Here are sample results:
I'm looking to expand my 'simple' photography events system to add the ability to add custom text to images we've shot. I technically have this aspect working using the existing picturebox control to display the image and a text box in which text can be entered and this will be added to the image being displayed.
However, being a photographer, I'd like the text to look a little nicer and as such am looking to emulate what I can do in Photoshop, i.e. bevel/emboss, add inner glows and drop shadows to this text but I'm struggling to find any references to this.
I may be simply limited by the fact I'm using winforms and this may have been achievable via WPF, but WPF wasn't about when I stopped being a programmer for a profession and as such stuck to technology I knew... I'm also far too far down the line in the system to re-write it all in WPF, so if its a limitation I'll just look at adding in pre-determined overlays rather than custom text which I know I can achieve.
The code I have so far is as follows and any tips on how to expand this to perform the bevel/emboss, glows etc would be much appreciated.
public static Bitmap addTexttoImage(string imagename, string textnya)
{
float fontSize = 80;
string imagepath = imagename;
Image image = Image.FromStream(new MemoryStream(File.ReadAllBytes(imagepath)));
//read the image we pass
Bitmap bmp = (Bitmap)Image.FromFile(imagepath);
Graphics g = Graphics.FromImage(bmp);
//this will centre align our text at the bottom of the image
StringFormat sf = new StringFormat();
sf.Alignment = StringAlignment.Center;
sf.LineAlignment = StringAlignment.Far;
//define a font to use.
Font f = new Font("Impact", fontSize, FontStyle.Bold, GraphicsUnit.Pixel);
//pen for outline - set width parameter
Pen p = new Pen(ColorTranslator.FromHtml("#77090C"), 8);
p.LineJoin = LineJoin.Round; //prevent "spikes" at the path
//this makes the gradient repeat for each text line
Rectangle fr = new Rectangle(0, bmp.Height - f.Height, bmp.Width, f.Height);
LinearGradientBrush b = new LinearGradientBrush(fr,
ColorTranslator.FromHtml("#FF6493"),
ColorTranslator.FromHtml("#D00F14"),
90);
//this will be the rectangle used to draw and auto-wrap the text.
//basically = image size
Rectangle r = new Rectangle(0, 0, bmp.Width, bmp.Height);
GraphicsPath gp = new GraphicsPath();
gp.AddString(textnya, f.FontFamily, (int)FontStyle.Bold, fontSize, r, sf);
g.SmoothingMode = SmoothingMode.AntiAlias;
g.PixelOffsetMode = PixelOffsetMode.HighQuality;
g.DrawPath(p, gp);
g.FillPath(b, gp);
//cleanup
gp.Dispose();
b.Dispose();
b.Dispose();
f.Dispose();
sf.Dispose();
g.Dispose();
return bmp;
}
In my application, I generate a Bitmap with a variable string.
Here is my function:
public void Image(String text, String font, int size)
{
Font font = new Font(font, size);
float res = ((font.SizeInPoints * text.Length) / 72) * 96;
using (Bitmap img = new Bitmap((int)res, font.Height))
{
Graphics g = Graphics.FromImage(img);
SolidBrush drawBrush = new SolidBrush(Color.Black);
g.DrawString(text, font, drawBrush, 1, 0);
String directory = AppDomain.CurrentDomain.BaseDirectory + "Content\\Images\\Signature\\";
string outputFileName = directory + "sign.png";
img.Save(outputFileName, ImageFormat.Png);
}
}
I would like the width of the image to match perfectly the width of the string printed in that bitmap.
As you can see, I tried to calculate the width with point size of the font.
The problem is that each letter printed has a different width so I can not get the size before creating the Bitmap.
Plus, I don't even know how to retrieve the actual size of the printed string...
Does anyone have an idea?
Use the Graphics.MeasureString function. It takes a string and a font, and returns the size of the rendered text as a SizeF. There are also additional overloads that can take formatting information, and one that takes a SizeF representing the maximum width for wrapping.
Details can be found here: https://msdn.microsoft.com/en-us/library/6xe5hazb(v=vs.110).aspx
// Set up string.
string measureString = "Measure String";
Font stringFont = new Font("Arial", 16);
// Set maximum layout size.
SizeF layoutSize = new SizeF(100.0F, 200.0F);
// Set string format.
StringFormat newStringFormat = new StringFormat();
newStringFormat.FormatFlags = StringFormatFlags.DirectionVertical;
// Measure string.
SizeF stringSize = new SizeF();
stringSize = e.Graphics.MeasureString(measureString, stringFont, layoutSize, newStringFormat);
// Draw rectangle representing size of string.
e.Graphics.DrawRectangle(new Pen(Color.Red, 1), 0.0F, 0.0F, stringSize.Width, stringSize.Height);
// Draw string to screen.
e.Graphics.DrawString(measureString, stringFont, Brushes.Black, new PointF(0,
Anyone ever wrote a C# GDI+ function to curl the corner of a BITMAP. I need to be able to take a static image and apply the peel effect to it on the bottom right corner. And I need to do it with C# all my searching leads to CSS3/FLASH/SilverLight virtual book type examples. I just want to create a static image that has a curled up corner and save the file.
Any Ideas?
Ok so I made the image with photo shop so that I can show you what I am trying to achieve
I start this image
and I want to write some C# code that would yield this image
The end result is just an image that is not animated, and does nothing. Any thoughts.
There are some good tools to do this, such as Fred's ImageMagick plugin script, but here is a C# version as requested.
using System.Drawing.Imaging;
public partial class ImagePeelEffect : Form
{
string WorkingDirectory = #"C:\temp\";
public ImagePeelEffect()
{
InitializeComponent();
}
private void ImagePeelEffect_Load(object sender, EventArgs e)
{
picBefore.Image = Image.FromFile(WorkingDirectory + "\\before.jpg");
}
private void button1_Click(object sender, EventArgs e)
{
//create a image object containing the photograph to add page peel effect
Image imgPhoto = Image.FromFile(WorkingDirectory + "\\before.jpg");
int phWidth = imgPhoto.Width;
int phHeight = imgPhoto.Height;
//create a Bitmap the Size of the original photograph
Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
//load the Bitmap into a Graphics object
Graphics grPhoto = Graphics.FromImage(bmPhoto);
//create a image object containing the PagePeel
Image imgPagePeel = new Bitmap(WorkingDirectory + "\\PagePeel.bmp");
int ppWidth = imgPagePeel.Width;
int ppHeight = imgPagePeel.Height;
//Set the rendering quality for this Graphics object
grPhoto.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
//Draws the photo Image object at original size to the graphics object.
grPhoto.DrawImage(
imgPhoto, // Photo Image object
new Rectangle(0, 0, phWidth, phHeight), // Rectangle structure
0, // x-coordinate of the portion of the source image to draw.
0, // y-coordinate of the portion of the source image to draw.
phWidth, // Width of the portion of the source image to draw.
phHeight, // Height of the portion of the source image to draw.
GraphicsUnit.Pixel); // Units of measure
//The first step in manipulating the PagePeel image is to replace
//the background color with one that is transparent (Alpha=0, R=0, G=0, B=0)
//to do this we will use a Colormap and define ImageAttributes with a RemapTable
ImageAttributes imageAttributes = new ImageAttributes();
ColorMap colorMap = new ColorMap();
//My PagePeel was defined with a background of 100% Green this will
//be the color we search for and replace with transparency
colorMap.OldColor = Color.FromArgb(255, 0, 255, 0);
colorMap.NewColor = Color.FromArgb(0, 0, 0, 0);
//Set the Remap Table with the old and new color map
ColorMap[] remapTable = { colorMap };
imageAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap);
//For this example we will place the PagePeel in the bottom right
//hand corner of the photograph
int xPosOfPp = phWidth - ppWidth;
int yPosOfPp = phHeight - ppHeight + 1;
grPhoto.DrawImage(imgPagePeel,
new Rectangle(xPosOfPp, yPosOfPp, ppWidth, ppHeight), //Set the detination Position
0, // x-coordinate of the portion of the source image to draw.
0, // y-coordinate of the portion of the source image to draw.
ppWidth, // PagePeel Width
ppHeight, // PagePeel Height
GraphicsUnit.Pixel, // Unit of measurment
imageAttributes); //ImageAttributes Object
//Replace the original photgraphs bitmap with the new Bitmap
imgPhoto = bmPhoto;
grPhoto.Dispose();
//save new image to file system.
imgPhoto.Save(WorkingDirectory + "\\after.jpg", ImageFormat.Jpeg);
imgPhoto.Dispose();
imgPagePeel.Dispose();
//Show the After image
picAfter.Image = Image.FromFile(WorkingDirectory + "\\after.jpg");
}
The PagePeel.bmp:
The Before and After result:
Update
Here's a version that uses a Transparent Page Peel overlay so you dont neet to convert the "green screen" to invisible. The advantage of this method is when the original photograph contains the colour green RGB(0,255,0) it wont be turned into transparent:
TransparentPagePeel.png:
private void button2_Click(object sender, EventArgs e)
{
//create a image object containing the photograph to add page peel effect
Image imgPhoto = Image.FromFile(WorkingDirectory + "\\before.jpg");
int phWidth = imgPhoto.Width;
int phHeight = imgPhoto.Height;
//create a Bitmap the Size of the original photograph
Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
//load the Bitmap into a Graphics object
Graphics grPhoto = Graphics.FromImage(bmPhoto);
//create a image object containing the PagePeel
Image imgPagePeel = new Bitmap(WorkingDirectory + "\\transparentPagePeel.png");
int ppWidth = imgPagePeel.Width;
int ppHeight = imgPagePeel.Height;
//Set the rendering quality for this Graphics object
grPhoto.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
//Draws the photo Image object at original size to the graphics object.
grPhoto.DrawImage(
imgPhoto, // Photo Image object
new Rectangle(0, 0, phWidth, phHeight), // Rectangle structure
0, // x-coordinate of the portion of the source image to draw.
0, // y-coordinate of the portion of the source image to draw.
phWidth, // Width of the portion of the source image to draw.
phHeight, // Height of the portion of the source image to draw.
GraphicsUnit.Pixel); // Units of measure
//For this example we will place the PagePeel in the bottom right
//hand corner of the photograph
int xPosOfPp = phWidth - ppWidth;
int yPosOfPp = phHeight - ppHeight + 1;
grPhoto.DrawImage(imgPagePeel,
new Rectangle(xPosOfPp, yPosOfPp, ppWidth, ppHeight), //Set the detination Position
0, // x-coordinate of the portion of the source image to draw.
0, // y-coordinate of the portion of the source image to draw.
ppWidth, // PagePeel Width
ppHeight, // PagePeel Height
GraphicsUnit.Pixel, // Unit of measurment
null); //ImageAttributes Object
//Replace the original photgraphs bitmap with the new Bitmap
imgPhoto = bmPhoto;
grPhoto.Dispose();
//save new image to file system.
imgPhoto.Save(WorkingDirectory + "\\after1.jpg", ImageFormat.Jpeg);
imgPhoto.Dispose();
imgPagePeel.Dispose();
picAfter.Image = Image.FromFile(WorkingDirectory + "\\after1.jpg");
}
I set copyright on the image. After that i need to delete the old file. But i can't because it's busy.
I need rename the copyrighted file from "copyrighted_"+imageFile to imageFile.
public static void SetImageCopyright(string imageFile)
{
#region
//create a image object containing the photograph to watermark
Image imgPhoto = Image.FromFile(imageFile);
int phWidth = imgPhoto.Width;
int phHeight = imgPhoto.Height;
//create a Bitmap the Size of the original photograph
Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
//load the Bitmap into a Graphics object
Graphics grPhoto = Graphics.FromImage(bmPhoto);
//------------------------------------------------------------
//Step #1 - Insert Copyright message
//------------------------------------------------------------
//Set the rendering quality for this Graphics object
grPhoto.SmoothingMode = SmoothingMode.AntiAlias;
//Draws the photo Image object at original size to the graphics object.
grPhoto.DrawImage(
imgPhoto, // Photo Image object
new Rectangle(0, 0, phWidth, phHeight), // Rectangle structure
0, // x-coordinate of the portion of the source image to draw.
0, // y-coordinate of the portion of the source image to draw.
phWidth, // Width of the portion of the source image to draw.
phHeight, // Height of the portion of the source image to draw.
GraphicsUnit.Pixel); // Units of measure
//-------------------------------------------------------
//to maximize the size of the Copyright message we will
//test multiple Font sizes to determine the largest posible
//font we can use for the width of the Photograph
//define an array of point sizes you would like to consider as possiblities
//-------------------------------------------------------
int[] sizes = new int[] { 25, 16, 12, 10, 8, 6, 4 };
Font crFont = null;
SizeF crSize = new SizeF();
//Loop through the defined sizes checking the length of the Copyright string
//If its length in pixles is less then the image width choose this Font size.
for (int i = 0; i < 7; i++)
{
//set a Font object to Arial (i)pt, Bold
crFont = new Font("arial", sizes[i], FontStyle.Bold);
//Measure the Copyright string in this Font
crSize = grPhoto.MeasureString("AlexMaslakov.ru", crFont);
if ((ushort)crSize.Width < (ushort)phWidth)
break;
}
//Since all photographs will have varying heights, determine a
//position 5% from the bottom of the image
int yPixlesFromBottom = (int)(phHeight * .05);
//Now that we have a point size use the Copyrights string height
//to determine a y-coordinate to draw the string of the photograph
float yPosFromBottom = ((phHeight - yPixlesFromBottom) - (crSize.Height / 2));
//Determine its x-coordinate by calculating the center of the width of the image
float xCenterOfImg = (phWidth / 2);
//Define the text layout by setting the text alignment to centered
StringFormat StrFormat = new StringFormat();
StrFormat.Alignment = StringAlignment.Center;
//define a Brush which is semi trasparent black (Alpha set to 153)
SolidBrush semiTransBrush2 = new SolidBrush(Color.FromArgb(153, 0, 0, 0));
//Draw the Copyright string
//grPhoto.DrawString(Copyright, //string of text
// crFont, //font
// semiTransBrush2, //Brush
// new PointF(xCenterOfImg + 5, yPosFromBottom + 5), //Position
// StrFormat);
//define a Brush which is semi trasparent white (Alpha set to 153)
SolidBrush semiTransBrush = new SolidBrush(Color.FromArgb(153, 255, 255, 255));
//Draw the Copyright string a second time to create a shadow effect
//Make sure to move this text 1 pixel to the right and down 1 pixel
grPhoto.DrawString("AlexMaslakov.ru", //string of text
crFont, //font
semiTransBrush, //Brush
new PointF(xCenterOfImg, yPosFromBottom), //Position
StrFormat); //Text alignment
//------------------------------------------------------------
//Step #2 - Insert Watermark image
//------------------------------------------------------------
//Create a Bitmap based on the previously modified photograph Bitmap
Bitmap bmWatermark = new Bitmap(bmPhoto);
bmWatermark.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
//Load this Bitmap into a new Graphic Object
Graphics grWatermark = Graphics.FromImage(bmWatermark);
//To achieve a transulcent watermark we will apply (2) color
//manipulations by defineing a ImageAttributes object and
//seting (2) of its properties.
ImageAttributes imageAttributes = new ImageAttributes();
//The first step in manipulating the watermark image is to replace
//the background color with one that is trasparent (Alpha=0, R=0, G=0, B=0)
//to do this we will use a Colormap and use this to define a RemapTable
ColorMap colorMap = new ColorMap();
//My watermark was defined with a background of 100% Green this will
//be the color we search for and replace with transparency
colorMap.OldColor = Color.FromArgb(255, 0, 255, 0);
colorMap.NewColor = Color.FromArgb(0, 0, 0, 0);
ColorMap[] remapTable = { colorMap };
imageAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap);
//The second color manipulation is used to change the opacity of the
//watermark. This is done by applying a 5x5 matrix that contains the
//coordinates for the RGBA space. By setting the 3rd row and 3rd column
//to 0.3f we achive a level of opacity
float[][] colorMatrixElements = {
new float[] {1.0f, 0.0f, 0.0f, 0.0f, 0.0f},
new float[] {0.0f, 1.0f, 0.0f, 0.0f, 0.0f},
new float[] {0.0f, 0.0f, 1.0f, 0.0f, 0.0f},
new float[] {0.0f, 0.0f, 0.0f, 0.3f, 0.0f},
new float[] {0.0f, 0.0f, 0.0f, 0.0f, 1.0f}};
ColorMatrix wmColorMatrix = new ColorMatrix(colorMatrixElements);
imageAttributes.SetColorMatrix(wmColorMatrix, ColorMatrixFlag.Default,
ColorAdjustType.Bitmap);
#endregion
//Replace the original photgraphs bitmap with the new Bitmap
imgPhoto = bmWatermark;
grPhoto.Dispose();
grWatermark.Dispose();
bmPhoto.Dispose();
//save new image to file system.
imgPhoto.Save("copyrighted_"+imageFile, ImageFormat.Jpeg);
imgPhoto.Dispose();
}
When you use Image.FromFile, the file is open as long as the image object exists. You have to dispose the image before you can replace the file.
The image that you loaded is never disposed in the code, you just replace the reference to it with the watermarked image. Dispose the image before discarding the reference to it:
//Replace the original photgraphs bitmap with the new Bitmap
imgPhoto.Dispose();
imgPhoto = bmWatermark;
Now you can save the image replacing the original file.
You open the file imgPhoto and try to Save it, while it is still open (it isn't disposed).
What you could do is open the file to a MemoryStream and create an Image from the stream.
After that, you can save it to the original file by overwriting it.
// Open the file here
Image original = Image.FromFile(file);
// Create a MemoryStream in which to save the image
MemoryStream originalStream = new MemoryStream();
// Save the Image to the MemoryStream
original.Save(originalStream, original.RawFormat);
// Dispose the original image, so you can overwrite it later
original.Dispose();
Now you can use the Image.FromStream method to create an Image which you can manipulate.
I'm no C# expert but it looks like you're not disposing the original image since near the end you just reassign the variable: imgPhoto = bmWatermark;
Try using a new variable rather than resusing imgPhoto and dispose of both at the end before deleting.
Files can't be "busy", but "locked".
Make sure no other application holds your file open, and make sure that you Dispose all file handles to that file, before attempting to do further things with that file.
If you can't find who has locked your file, you could try "process explorer".