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");
}
Related
I have a picture I want to print, but it's too big for one page
so i have decided to split it into multiple images
i have tried a method, but now im using this (Talha Irfan answer)
i also tried the other solutions there but those didnt worked as well
(ex. bm.Clone(rec, bm.PixelFormat);)
and here's my code(this is on non-form class)
Bitmap bm = new Bitmap(frmPrint.Width, frmPrint.Height);
Rectangle rec = new Rectangle(0, 200, 576, 300);
Bitmap bitmap = cropImg(bm, rec);
frmPrint.DrawToBitmap(bitmap, rec);
frmPrint._img = bitmap;
frmPrint.setImage();
and setImage function(on some form)
public void setImage()
{
pictureBox3.BackgroundImage = _img;
this.ShowDialog();
}
and cropImg is the same as cropAtRect
the below shows the original image (on the left)
the wanted result in the blue rectangle
and the actual result on the right
PS
my actual image size is (height = 698, wifht = 576)
Edit - as suggested below
on non-form class
Rectangle cropRect = new Rectangle(0, 0, 576, 698);
Bitmap target = new Bitmap(cropRect.Width, cropRect.Height, bm.PixelFormat);
frmPrint.setImage(bm, target, cropRect);
target.Dispose();
at form class
public void setImage(Bitmap src, Bitmap target, Rectangle cropRect)
{
pictureBox3.Visible = false;
using (Graphics g = Graphics.FromImage(target))
{
g.DrawImage(src, new Rectangle(pictureBox3.Location.X, pictureBox3.Location.Y, target.Width, target.Height),
cropRect,
GraphicsUnit.Pixel);
}
this.ShowDialog();
}
Control.DrawToBitmap will always try to draw the whole control or form and will always start at the top. The parameter:
targetBounds
Type: System.Drawing.Rectangle
The bounds within which the control is rendered.
as the name implies, sets the target, not the source rectangle. Hence the white space above your result.
Move the line before cropping with a rectangle that holds the full area, maybe like this:
DrawToBitmap(bm, ClientRectangle);
and then crop the lower part as before..
Note that the cropping trick from your link will not work for DrawToBitmap; using a rectangle with a negative offset will cause a parameter exception.
Btw: to safely dispose of a Bitmap in a PictureBox use this:
Bitmap dummy = (Bitmap )somePictureBox.Image;
somePictureBox.Image = null;
if (dummy != null) dummy.Dispose;
And, indeed, the answer by ChrisJJ in the link leaks the Graphics object.
Update:
Since you seem to have lost control over the various changes and suggestions, here is the minimal code change from the original post:
Bitmap bm = new Bitmap(frmPrint.ClientWidth, frmPrint.ClientHeight);
DrawToBitmap(bm, frmPrint.ClientRectangle);
Rectangle rec = new Rectangle(0, 200, 576, 300);
Bitmap bitmap = cropImg(bm, rec);
frmPrint._img = bitmap;
frmPrint.setImage();
With:
public void setImage()
{
Bitmap dummy = pictureBox3.BackgroundImage;
pictureBox3.BackgroundImage = null;
if (dummy != bnull) dummy.Dispose();
pictureBox3.BackgroundImage = _img;
this.ShowDialog();
}
In the cropImg function add a g.Dispose before returning.
Never really worked with Graphics before. I have looked around on this and pieced together a few solutions from answers which address small parts of my question. but none have worked.
I want to load an image from a file, which will always be 320x240 in size. I then want to crop it to obtain a 240x240 image, with the outer 40px on each side trimmed. After this is done I want to save as a new image.
private void croptoSquare(string date)
{
//Location of 320x240 image
string fileName = Server.MapPath("~/Content/images/" + date + "contactimage.jpg");
//New rectangle of final size (I think maybe Point is where I would eventually specify where the crop square site i.e. (40, 0))
Rectangle cropRect = new Rectangle(new Point(0, 0), new Size(240, 240));
//Create a Bitmap with correct height/width.
Bitmap target = new Bitmap(cropRect.Width, cropRect.Height);
//Load image from file
using (Image image = Image.FromFile(fileName))
{
//Create Graphics object from image
using (Graphics graphic = Graphics.FromImage(image))
{
//Not sure what this does, I found it on a post.
graphic.DrawImage(image,
cropRect,
new Rectangle(0, 0, target.Width, target.Height),
GraphicsUnit.Pixel);
fileName = Server.MapPath("~/Content/images/" + date + "contactimagecropped.jpg");
image.Save(fileName);
}
}
}
Currently it is simply resaving the same image and I'm not sure why. I have specified a destination rectangle as 240x240 and a src rectangle as 320x240.
As I say I know basically nothing about working with graphics objects so I imagine this is blatant.
Can anybody tell me how to achieve what I want?
private void croptoSquare(string date)
{
//Location of 320x240 image
string fileName = Server.MapPath("~/Content/images/" + date + "contactimage.jpg");
// Create a new image at the cropped size
Bitmap cropped = new Bitmap(240,240);
//Load image from file
using (Image image = Image.FromFile(fileName))
{
// Create a Graphics object to do the drawing, *with the new bitmap as the target*
using (Graphics g = Graphics.FromImage(cropped) )
{
// Draw the desired area of the original into the graphics object
g.DrawImage(image, new Rectangle(0, 0, 240, 240), new Rectangle(40, 0, 240, 240), GraphicsUnit.Pixel);
fileName = Server.MapPath("~/Content/images/" + date + "contactimagecropped.jpg");
// Save the result
cropped.Save(fileName);
}
}
}
Why don't you use JCrop instead? http://www.programmerclubhouse.com/index.php/crop-image-using-jcrop-in-asp-net-c-shar/
I need to fill an rectangle on bottom of my image, but not over the image, so it should be a kind of append a rectangle to bottom of image.
What I have for now:
private void DrawRectangle()
{
string imageFilePath = #"c:\Test.jpg";
Bitmap bitmap = (Bitmap)Image.FromFile(imageFilePath);
using (Graphics graphics = Graphics.FromImage(bitmap))
{
using (Image img = Image.FromFile(imageFilePath))
{
SolidBrush brush = new SolidBrush(Color.Black);
int width = img.Width;
int height = img.Height - 350;
graphics.FillRectangle(brush, 0, height, width, 350);
}
}
bitmap.Save(#"c:\Test1.jpg");
}
But this is over the image.
Any idea's?
Thank you.
You need to know the dimensions of your original image in order to set the size of the new bitmap, which must be larger to accommodate the rectangle.
private void DrawRectangle()
{
string imageFilePath = #"c:\Test.jpg";
int rectHeight = 100;
using (Image img = Image.FromFile(imageFilePath)) // load original image
using (Bitmap bitmap = new Bitmap(img.Width, img.Height + rectHeight)) // create blank bitmap of desired size
using (Graphics graphics = Graphics.FromImage(bitmap))
{
// draw existing image onto new blank bitmap
graphics.DrawImage(img, 0, 0, img.Width, img.Height);
SolidBrush brush = new SolidBrush(Color.Black);
// draw your rectangle below the original image
graphics.FillRectangle(brush, 0, img.Height, img.Width, rectHeight);
bitmap.Save(#"c:\Test1.bmp");
}
}
take a look at the FillRectangle() method overloads.. it has one with the following definition: FillRectangle(Brush brush, int PositionX, int PositionY, int Width, int Height)
your problem most likely stems on using an improper overload for what you're doing.
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.
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".