Resize image proportionally with MaxHeight and MaxWidth constraints - c#

Using System.Drawing.Image.
If an image width or height exceed the maximum, it need to be resized proportionally .
After resized it need to make sure that neither width or height still exceed the limit.
The Width and Height will be resized until it is not exceed to maximum and minimum automatically (biggest size possible) and also maintain the ratio.

Like this?
public static void Test()
{
using (var image = Image.FromFile(#"c:\logo.png"))
using (var newImage = ScaleImage(image, 300, 400))
{
newImage.Save(#"c:\test.png", ImageFormat.Png);
}
}
public static Image ScaleImage(Image image, int maxWidth, int maxHeight)
{
var ratioX = (double)maxWidth / image.Width;
var ratioY = (double)maxHeight / image.Height;
var ratio = Math.Min(ratioX, ratioY);
var newWidth = (int)(image.Width * ratio);
var newHeight = (int)(image.Height * ratio);
var newImage = new Bitmap(newWidth, newHeight);
using (var graphics = Graphics.FromImage(newImage))
graphics.DrawImage(image, 0, 0, newWidth, newHeight);
return newImage;
}

Much longer solution, but accounts for the following scenarios:
Is the image smaller than the bounding box?
Is the Image and the Bounding Box square?
Is the Image square and the bounding box isn't
Is the image wider and taller than the bounding box
Is the image wider than the bounding box
Is the image taller than the bounding box
private Image ResizePhoto(FileInfo sourceImage, int desiredWidth, int desiredHeight)
{
//throw error if bouning box is to small
if (desiredWidth < 4 || desiredHeight < 4)
throw new InvalidOperationException("Bounding Box of Resize Photo must be larger than 4X4 pixels.");
var original = Bitmap.FromFile(sourceImage.FullName);
//store image widths in variable for easier use
var oW = (decimal)original.Width;
var oH = (decimal)original.Height;
var dW = (decimal)desiredWidth;
var dH = (decimal)desiredHeight;
//check if image already fits
if (oW < dW && oH < dH)
return original; //image fits in bounding box, keep size (center with css) If we made it bigger it would stretch the image resulting in loss of quality.
//check for double squares
if (oW == oH && dW == dH)
{
//image and bounding box are square, no need to calculate aspects, just downsize it with the bounding box
Bitmap square = new Bitmap(original, (int)dW, (int)dH);
original.Dispose();
return square;
}
//check original image is square
if (oW == oH)
{
//image is square, bounding box isn't. Get smallest side of bounding box and resize to a square of that center the image vertically and horizontally with Css there will be space on one side.
int smallSide = (int)Math.Min(dW, dH);
Bitmap square = new Bitmap(original, smallSide, smallSide);
original.Dispose();
return square;
}
//not dealing with squares, figure out resizing within aspect ratios
if (oW > dW && oH > dH) //image is wider and taller than bounding box
{
var r = Math.Min(dW, dH) / Math.Min(oW, oH); //two dimensions so figure out which bounding box dimension is the smallest and which original image dimension is the smallest, already know original image is larger than bounding box
var nH = oH * r; //will downscale the original image by an aspect ratio to fit in the bounding box at the maximum size within aspect ratio.
var nW = oW * r;
var resized = new Bitmap(original, (int)nW, (int)nH);
original.Dispose();
return resized;
}
else
{
if (oW > dW) //image is wider than bounding box
{
var r = dW / oW; //one dimension (width) so calculate the aspect ratio between the bounding box width and original image width
var nW = oW * r; //downscale image by r to fit in the bounding box...
var nH = oH * r;
var resized = new Bitmap(original, (int)nW, (int)nH);
original.Dispose();
return resized;
}
else
{
//original image is taller than bounding box
var r = dH / oH;
var nH = oH * r;
var nW = oW * r;
var resized = new Bitmap(original, (int)nW, (int)nH);
original.Dispose();
return resized;
}
}
}

Working Solution :
For Resize image with size lower then 100Kb
WriteableBitmap bitmap = new WriteableBitmap(140,140);
bitmap.SetSource(dlg.File.OpenRead());
image1.Source = bitmap;
Image img = new Image();
img.Source = bitmap;
WriteableBitmap i;
do
{
ScaleTransform st = new ScaleTransform();
st.ScaleX = 0.3;
st.ScaleY = 0.3;
i = new WriteableBitmap(img, st);
img.Source = i;
} while (i.Pixels.Length / 1024 > 100);
More Reference at http://net4attack.blogspot.com/

Related

Calculate Crop Rectangle that has been zoomed and resized

I'm working on an image viewer in C# WPF that can zoom and crop images. I'd like to be able to make the two work together, but I don't know how to calculate that.
To zoom an image, it is done by modifying TranslateTransform and ScaleTransform X & Y values. Inspired by this answer https://stackoverflow.com/a/6782715/2923736
The crop function is done by calculating TopLeftX, TopRightY, BottomRightX, BottomLeftY that has been drawn on screen.
The size and aspect ratio calculation is done like so:
maxWidth = Math.Min(ScreenWidth, imageWidth);
maxHeight = Math.Min(ScreenHeight, imageHeight);
AspectRatio = Math.Min(maxWidth / imageWidth, maxHeight / imageHeight);
ImageWidth = imageWidth * AspectRatio;
ImageHeight = imageHeight * AspectRatio;
I use this code to calculate the cropped area, but don't know how to put TranslateTransform and ScaleTransform X & Y values into the formula.
internal static Int32Rect? GetCrop()
{
// Contains the dimensions and coordinates of cropped area
var cropArea = CropService.GetCroppedArea();
if (cropArea == null) { return null; }
int x, y, width, height;
x = Convert.ToInt32(cropArea.CroppedRectAbsolute.X / AspectRatio);
y = Convert.ToInt32(cropArea.CroppedRectAbsolute.Y / AspectRatio);
switch (Rotateint) // Degress the image has been rotated by
{
case 0:
case 180:
width = Convert.ToInt32(cropArea.CroppedRectAbsolute.Width / AspectRatio);
height = Convert.ToInt32(cropArea.CroppedRectAbsolute.Height / AspectRatio);
break;
default:
width = Convert.ToInt32(cropArea.CroppedRectAbsolute.Height / AspectRatio);
height = Convert.ToInt32(cropArea.CroppedRectAbsolute.Width / AspectRatio);
break;
}
return new Int32Rect(x, y, width, height);
}
Example of image being cropped, where it has been resized to fit the window and zoomed in by 20%.
I need to calculate that, so it can be saved on the user's hard disk.

How to pass own method with width and height parameters into button click

I want to insert two different sizes of images using single file upload.
I had inserted one image which has size 101 but I need to insert another 51 size small image of the same user, for that I need my own method.
id BigImage SmallImage
1 mazhar.jpg NULL
2 12_n.jpg NULL
I need result like below:
id BigImage SmallImage
1 mazhar.jpg smallmazhar.jpg
2 12_n.jpg small12_n.jpg
C# code is given below:
protected void Button1_Click(object sender, EventArgs e)
{
//http://forums.asp.net/t/1079883.aspx?PageIndex=1
string Status = string.Empty;
int id = 0;
const int bmpW = 101;
//New image target width
const int bmpH = 101;
//New Image target height
bo.Para1 = FileUpload1.FileName.ToString();// Passing parameter
if ((FileUpload1.HasFile))
{
//Clear the error label text
lblError.Text = "";
//Check to make sure the file to upload has a picture file format extention and set the target width and height
if ((CheckFileType(FileUpload1.FileName)))
{
Int32 newWidth = bmpW;
Int32 newHeight = bmpH;
//Use the uploaded filename for saving without the '.' extension
String upName = FileUpload1.FileName.Substring(0, FileUpload1.FileName.IndexOf("."));
//Set the save path of the resized image, you will need this directory already created in your web site
// string filePath = "~/Upload/" + upName + ".jpg";
bl.Insert_PhotoInfo(bo, out Status, out id);
string filePath = Convert.ToString(id) + bo.Para1;
FileUpload1.PostedFile.SaveAs(Request.ServerVariables["APPL_PHYSICAL_PATH"] + "Upload/" + filePath);
//Create a new Bitmap using the uploaded picture as a Stream
//Set the new bitmap resolution to 72 pixels per inch
Bitmap upBmp = (Bitmap)Bitmap.FromStream(FileUpload1.PostedFile.InputStream);
Bitmap newBmp = new Bitmap(newWidth, newHeight, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
newBmp.SetResolution(72, 72);
//Get the uploaded image width and height
Double upWidth = upBmp.Width;
Double upHeight = upBmp.Height;
int newX = 0;
//Set the new top left drawing position on the image canvas
int newY = 0;
Double reDuce;
//Keep the aspect ratio of image the same if not 4:3 and work out the newX and newY positions
//to ensure the image is always in the centre of the canvas vertically and horizontally
if (upWidth > upHeight)
{
//Landscape picture
reDuce = newWidth / upWidth;
//calculate the width percentage reduction as decimal
newHeight = ((Int32)(upHeight * reDuce));
//reduce the uploaded image height by the reduce amount
newY = ((Int32)((bmpH - newHeight) / 2));
//Position the image centrally down the canvas
newX = 0;
//Picture will be full width
}
else if (upWidth < upHeight)
{
//Portrait picture
reDuce = newHeight / upHeight;
//calculate the height percentage reduction as decimal
newWidth = ((Int32)(upWidth * reDuce));
//reduce the uploaded image height by the reduce amount
newX = ((Int32)((bmpW - newWidth) / 2));
//Position the image centrally across the canvas
newY = 0;
//Picture will be full hieght
}
else if (upWidth == upHeight)
{
//square picture
reDuce = newHeight / upHeight;
//calculate the height percentage reduction as decimal
newWidth = ((Int32)(upWidth * reDuce));
//reduce the uploaded image height by the reduce amount
newX = ((Int32)((bmpW - newWidth) / 2));
//Position the image centrally across the canvas
newY = ((Int32)((bmpH - newHeight) / 2));
//Position the image centrally down the canvas
}
//Create a new image from the uploaded picture using the Graphics class
//Clear the graphic and set the background colour to white
//Use Antialias and High Quality Bicubic to maintain a good quality picture
//Save the new bitmap image using 'Png' picture format and the calculated canvas positioning
Graphics newGraphic = Graphics.FromImage(newBmp);
try
{
newGraphic.Clear(Color.White);
newGraphic.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
newGraphic.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
newGraphic.DrawImage(upBmp, newX, newY, newWidth, newHeight);
newBmp.Save(MapPath(filePath), System.Drawing.Imaging.ImageFormat.Jpeg);
//Show the uploaded resized picture in the image control
Image1.ImageUrl = filePath;
Image1.Visible = true;
}
catch (Exception ex)
{
string newError = ex.Message;
lblError.Text = newError;
}
finally
{
upBmp.Dispose();
newBmp.Dispose();
newGraphic.Dispose();
}
}
else
{
lblError.Text = "Please select a picture with a file format extension of either Bmp, Jpg, Jpeg, Gif or Png.";
}
}
}
Here is your updated code:
protected void Button1_Click(object sender, EventArgs e){
UploadImage(101, "Big");
UploadImage(51, "Small");
}
protected void UploadImage(int size, string name){
//http://forums.asp.net/t/1079883.aspx?PageIndex=1
string Status = string.Empty;
int id = 0;
const int bmpW = size;
//New image target width
const int bmpH = size;
//New Image target height
bo.Para1 = FileUpload1.FileName.ToString() + name;// Passing parameter
if ((FileUpload1.HasFile))
{
//Clear the error label text
lblError.Text = "";
//Check to make sure the file to upload has a picture file format extention and set the target width and height
if ((CheckFileType(FileUpload1.FileName)))
{
Int32 newWidth = bmpW;
Int32 newHeight = bmpH;
//Use the uploaded filename for saving without the '.' extension
String upName = FileUpload1.FileName.Substring(0, FileUpload1.FileName.IndexOf("."));
//Set the save path of the resized image, you will need this directory already created in your web site
// string filePath = "~/Upload/" + upName + ".jpg";
bl.Insert_PhotoInfo(bo, out Status, out id);
string filePath = Convert.ToString(id) + bo.Para1;
FileUpload1.PostedFile.SaveAs(Request.ServerVariables["APPL_PHYSICAL_PATH"] + "Upload/" + filePath);
//Create a new Bitmap using the uploaded picture as a Stream
//Set the new bitmap resolution to 72 pixels per inch
Bitmap upBmp = (Bitmap)Bitmap.FromStream(FileUpload1.PostedFile.InputStream);
Bitmap newBmp = new Bitmap(newWidth, newHeight, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
newBmp.SetResolution(72, 72);
//Get the uploaded image width and height
Double upWidth = upBmp.Width;
Double upHeight = upBmp.Height;
int newX = 0;
//Set the new top left drawing position on the image canvas
int newY = 0;
Double reDuce;
//Keep the aspect ratio of image the same if not 4:3 and work out the newX and newY positions
//to ensure the image is always in the centre of the canvas vertically and horizontally
if (upWidth > upHeight)
{
//Landscape picture
reDuce = newWidth / upWidth;
//calculate the width percentage reduction as decimal
newHeight = ((Int32)(upHeight * reDuce));
//reduce the uploaded image height by the reduce amount
newY = ((Int32)((bmpH - newHeight) / 2));
//Position the image centrally down the canvas
newX = 0;
//Picture will be full width
}
else if (upWidth < upHeight)
{
//Portrait picture
reDuce = newHeight / upHeight;
//calculate the height percentage reduction as decimal
newWidth = ((Int32)(upWidth * reDuce));
//reduce the uploaded image height by the reduce amount
newX = ((Int32)((bmpW - newWidth) / 2));
//Position the image centrally across the canvas
newY = 0;
//Picture will be full hieght
}
else if (upWidth == upHeight)
{
//square picture
reDuce = newHeight / upHeight;
//calculate the height percentage reduction as decimal
newWidth = ((Int32)(upWidth * reDuce));
//reduce the uploaded image height by the reduce amount
newX = ((Int32)((bmpW - newWidth) / 2));
//Position the image centrally across the canvas
newY = ((Int32)((bmpH - newHeight) / 2));
//Position the image centrally down the canvas
}
//Create a new image from the uploaded picture using the Graphics class
//Clear the graphic and set the background colour to white
//Use Antialias and High Quality Bicubic to maintain a good quality picture
//Save the new bitmap image using 'Png' picture format and the calculated canvas positioning
Graphics newGraphic = Graphics.FromImage(newBmp);
try
{
newGraphic.Clear(Color.White);
newGraphic.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
newGraphic.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
newGraphic.DrawImage(upBmp, newX, newY, newWidth, newHeight);
newBmp.Save(MapPath(filePath), System.Drawing.Imaging.ImageFormat.Jpeg);
//Show the uploaded resized picture in the image control
Image1.ImageUrl = filePath;
Image1.Visible = true;
}
catch (Exception ex)
{
string newError = ex.Message;
lblError.Text = newError;
}
finally
{
upBmp.Dispose();
newBmp.Dispose();
newGraphic.Dispose();
}
}
else
{
lblError.Text = "Please select a picture with a file format extension of either Bmp, Jpg, Jpeg, Gif or Png.";
}
}
}

ImageLayout.Center does not center background image

I want to center a background image. However the background image is larger than my control(which is a flat style checkbox).
A picture to make my problem clear
Usually if the background image is smaller than the control, it will be shown like the black box(which is properly centered); but in my case it will show partial image in the green box(left top corner), but the end result I want is the orange box(the center of the image), or zoomed proportionally to fill the control with extra part cut off(ImageLayout.Zoom will show whole image with blank space).
Update: Code used:
Image img = Image.FromFile("xxxx.png");
mycheckbox.BackgroundImage = img;
mycheckbox.BackgroundImageLayout = ImageLayout.Center;
Image can be used instead of BackgroundImage to get the part of the image as the orange rectangle of the example.
If the image doesn't fill the entire checkbox and if it's acceptable to alter the image being set (should work without problems, but would not be dynamic in case the checkbox size changes during runtime), the image could be resized first according to the largest ratio:
var img = Image.FromFile("xxxx.png");
float ratio = Math.Max(mycheckbox.Height / (float)img.Height,mycheckbox.Width / (float)img.Width);
if (ratio > 1)
{
Func<float, int> calc = f => (int)Math.Ceiling(f * ratio);
var bmp = new Bitmap(img, calc(img.Width ), calc(img.Height ));
img.Dispose();
img = bmp;
}
mycheckbox.ImageAlign = ContentAlignment.MiddleCenter;
mycheckbox.Image = img;
The line float ratio = Math.Max(mycheckbox.Height / (float)img.Height,mycheckbox.Width / (float)img.Width); simply calculates both the height ratio and the width ratio. If either is larger than 1, it means the checkbox height or width is larger. It doesn't matter which one, only which is larger, hence the Math.Max. The check of larger than 1 is performed on the largest ratio and if needed the image is enlarged with said ratio.
Edit A more generic approach, that scales and cuts the image so that if fills the control size and the BackGroundImage property can be used:
public static void SetImage(this Control ctrl, Image img)
{
var cs = ctrl.Size;
if (img.Size != cs)
{
float ratio = Math.Max(cs.Height / (float)img.Height, cs.Width / (float)img.Width);
if (ratio > 1)
{
Func<float, int> calc = f => (int)Math.Ceiling(f * ratio);
img = new Bitmap(img, calc(img.Width), calc(img.Height));
}
var part = new Bitmap(cs.Width, cs.Height);
using (var g = Graphics.FromImage(part))
{
g.DrawImageUnscaled(img, (cs.Width - img.Width) /2, (cs.Height - img.Height) / 2);
}
img = part;
}
ctrl.BackgroundImageLayout = ImageLayout.Center;
ctrl.BackgroundImage = img;
}

ListView Larget Icon vertical alignment of the images

I have ListView with the View type LargeIcon. The ListView has assigned LargeImageList. The assigned ImageList has ImageSize 200x200.
Images that will be added to the ImageList have size that doesn't match to 200x200 ImageList size. They can have a lesser width or height. In both cases I want images to be aligned by center, i.e. MiddleCenter property for Winforms.Label class
ImageList will resize the image to fit the ImageSize. To get the image at its original size, and centered, you'll need to create a new image with the desired properties. Sample code to do this (untested):
public static void AddCenteredImage(ImageList list, Image image) {
using (var bmp = new Bitmap(list.ImageSize.Width, list.ImageSize.Height))
using (var gr = Graphics.FromImage(bmp)) {
gr.Clear(Color.Transparent); // Change background if necessary
var size = image.Size;
if (size.Width > list.ImageSize.Width || size.Height > list.ImageSize.Height) {
// Image too large, rescale to fit the image list
double wratio = list.ImageSize.Width / size.Width;
double hratio = list.ImageSize.Height / size.Height;
double ratio = Math.Min(wratio, hratio);
size = new Size((int)(ratio * size.Width), (int)(ratio * size.Height));
}
var rc = new Rectangle(
(list.ImageSize.Width - size.Width) / 2,
(list.ImageSize.Height - size.Height) / 2,
size.Width, size.Height);
gr.DrawImage(image, rc);
list.Images.Add(bmp);
}
}

Image cropping in C#

I'am using PictureBox for displaying images. My images are direct from scanner so the resolutions are up to 4000*4000... Because my display area is a lot smaller I have to display the image with pictureBox1.SizeMode = PictureBoxSizeMode.Zoom; to preserve aspect ratio.
After that the image is in the middle of the screen.
How can I find the distance between the left side of the image control and the REAL left side of an actual image (see image bellow).
Is there any solution?
Btw. displaying the image on the left side of the screen would do the trick too.
var imageHeight = pictureBox1.Image.Height;
var imageWidth = pictureBox1.Image.Width;
var userSelection = rect.Rect;
var display = pictureBox1.DisplayRectangle;
var xFactor = (float)userSelection.Width / display.Width;
var yFactor = (float)userSelection.Height / display.Height;
var realCropSizeWidth = xFactor * imageWidth;
var realCropSizeHight = yFactor * imageHeight;
var realCropX = imageWidth / display.Width;
realCropX *= userSelection.X;
var realCropY = imageHeight / display.Height;
realCropY *= userSelection.Y;
var realCropRectangle = new Rectangle(realCropX, realCropY, (int)realCropSizeWidth,
(int)realCropSizeHight);
var image = CropImage(pictureBox1.Image, realCropRectangle);
pictureBox1.Image = image;
public Image CropImage(Image source, Rectangle rectangle)
{
var target = new Bitmap(rectangle.Width, rectangle.Height);
using (var g = Graphics.FromImage(target))
{
g.DrawImage(source, new Rectangle(0, 0, target.Width, target.Height),
rectangle,
GraphicsUnit.Pixel);
}
return target;
}
As far as I know there is no direct way of getting what you want, but some simple maths would suffice:
You know the aspect ratio of your original image which is preserved and you know the aspect ratio of your picturebox in which you are showing it. Based on that you can figure out which dimension (height or width) the image fits exactly. Once you know that you can obtain the scaling factor of the image and therefore you can calculate the other dimension of the shown image.
As the image will be centered on the dimension that is not fitted exactly to the picturebox, its straighforward to get the distance you are looking for.

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