I want to send an image to backend, but before sending user can select some part of it. And I need to remove unwanted part. Below I attached some screenshots.
After three days of working on it I finally found out, how to work around.
So if it's not an eraser I'm just drawing as always but if an eraser I'm replacing Paint with shader wich is my image from background.
if (!_eraser) {
paint = new Paint()
..style = PaintingStyle.fill
..strokeCap = StrokeCap.round
..color = selectedColor
..strokeWidth = strokeWidth;
} else {
final Float64List deviceTransform = new Float64List(16)
..[0] = devicePixelRatio
..[5] = devicePixelRatio
..[10] = 1.0
..[15] = 2.0;
paint = new Paint()
..style = PaintingStyle.fill
..strokeCap = StrokeCap.round
..shader = ImageShader(image, TileMode.repeated, TileMode.repeated, deviceTransform)
..strokeWidth = strokeWidth;
Painting Class
#override
void paint(Canvas canvas, Size size) {
canvas.drawImage(image, Offset.zero, new Paint());
for (int i = 0; i < pointsList.length - 1; i++) {
if (pointsList[i] != null && pointsList[i + 1] != null) {
canvas.drawLine(pointsList[i].points, pointsList[i + 1].points, pointsList[i].paint);
} else if (pointsList[i] != null && pointsList[i + 1] == null) {
offsetPoints.clear();
offsetPoints.add(pointsList[i].points);
offsetPoints.add(Offset(pointsList[i].points.dx + 0.1, pointsList[i].points.dy + 0.1));
canvas.drawCircle(pointsList[i].points, pointsList[i].paint.strokeWidth / 2, pointsList[i].paint);
}
}
}
If you want to crop the image basic on some user input that you already have, you could use the copyCrop function from the image library.
Related
I am trying to get an image using the camera. The image is to be 256x256 and I want it to come from the centre of a photo taken using the camera on a phone. I found this code at: https://forums.xamarin.com/discussion/37647/cross-platform-crop-image-view
I am using this code for Android...
public byte[] CropPhoto(byte[] photoToCropBytes, Rectangle rectangleToCrop, double outputWidth, double outputHeight)
{
using (var photoOutputStream = new MemoryStream())
{
// Load the bitmap
var inSampleSize = CalculateInSampleSize((int)rectangleToCrop.Width, (int)rectangleToCrop.Height, (int)outputWidth, (int)outputHeight);
var options = new BitmapFactory.Options();
options.InSampleSize = inSampleSize;
//options.InPurgeable = true; see http://developer.android.com/reference/android/graphics/BitmapFactory.Options.html
using (var photoToCropBitmap = BitmapFactory.DecodeByteArray(photoToCropBytes, 0, photoToCropBytes.Length, options))
{
var matrix = new Matrix();
var martixScale = outputWidth / rectangleToCrop.Width * inSampleSize;
matrix.PostScale((float)martixScale, (float)martixScale);
using (var photoCroppedBitmap = Bitmap.CreateBitmap(photoToCropBitmap, (int)(rectangleToCrop.X / inSampleSize), (int)(rectangleToCrop.Y / inSampleSize), (int)(rectangleToCrop.Width / inSampleSize), (int)(rectangleToCrop.Height / inSampleSize), matrix, true))
{
photoCroppedBitmap.Compress(Bitmap.CompressFormat.Jpeg, 100, photoOutputStream);
}
}
return photoOutputStream.ToArray();
}
}
public static int CalculateInSampleSize(int inputWidth, int inputHeight, int outputWidth, int outputHeight)
{
//see http://developer.android.com/training/displaying-bitmaps/load-bitmap.html
int inSampleSize = 1; //default
if (inputHeight > outputHeight || inputWidth > outputWidth) {
int halfHeight = inputHeight / 2;
int halfWidth = inputWidth / 2;
// Calculate the largest inSampleSize value that is a power of 2 and keeps both
// height and width larger than the requested height and width.
while ((halfHeight / inSampleSize) > outputHeight && (halfWidth / inSampleSize) > outputWidth)
{
inSampleSize *= 2;
}
}
return inSampleSize;
}
and this code for iOS...
public byte[] CropPhoto(byte[] photoToCropBytes, Xamarin.Forms.Rectangle
rectangleToCrop, double outputWidth, double outputHeight)
{
byte[] photoOutputBytes;
using (var data = NSData.FromArray(photoToCropBytes))
{
using (var photoToCropCGImage = UIImage.LoadFromData(data).CGImage)
{
//crop image
using (var photoCroppedCGImage = photoToCropCGImage.WithImageInRect(new CGRect((nfloat)rectangleToCrop.X, (nfloat)rectangleToCrop.Y, (nfloat)rectangleToCrop.Width, (nfloat)rectangleToCrop.Height)))
{
using (var photoCroppedUIImage = UIImage.FromImage(photoCroppedCGImage))
{
//create a 24bit RGB image to the output size
using (var cGBitmapContext = new CGBitmapContext(IntPtr.Zero, (int)outputWidth, (int)outputHeight, 8, (int)(4 * outputWidth), CGColorSpace.CreateDeviceRGB(), CGImageAlphaInfo.PremultipliedFirst))
{
var photoOutputRectangleF = new RectangleF(0f, 0f, (float)outputWidth, (float)outputHeight);
// draw the cropped photo resized
cGBitmapContext.DrawImage(photoOutputRectangleF, photoCroppedUIImage.CGImage);
//get cropped resized photo
var photoOutputUIImage = UIKit.UIImage.FromImage(cGBitmapContext.ToImage());
//convert cropped resized photo to bytes and then stream
using (var photoOutputNsData = photoOutputUIImage.AsJPEG())
{
photoOutputBytes = new Byte[photoOutputNsData.Length];
System.Runtime.InteropServices.Marshal.Copy(photoOutputNsData.Bytes, photoOutputBytes, 0, Convert.ToInt32(photoOutputNsData.Length));
}
}
}
}
}
}
return photoOutputBytes;
}
I am struggling to work out exactly what the parameters are to call the function.
Currently, I am doing the following:
double cropSize = Math.Min(DeviceDisplay.MainDisplayInfo.Width, DeviceDisplay.MainDisplayInfo.Height);
double left = (DeviceDisplay.MainDisplayInfo.Width - cropSize) / 2.0;
double top = (DeviceDisplay.MainDisplayInfo.Height - cropSize) / 2.0;
// Get a square resized and cropped from the top image as a byte[]
_imageData = mediaService.CropPhoto(_imageData, new Rectangle(left, top, cropSize, cropSize), 256, 256);
I was expecting this to crop the image to the central square (in portrait mode side length would be the width of the photo) and then scale it down to a 256x256 image. But it never picks the centre of the image.
Has anyone ever used this code and can tell me what I need to pass in for the 'rectangleToCrop' parameter?
Note: Both Android and iOS give the same image, just not the central part that I was expecting.
Here are the two routines I used:
Android:
public byte[] ResizeImageAndCropToSquare(byte[] rawPhoto, int outputSize)
{
// Create object of bitmapfactory's option method for further option use
BitmapFactory.Options options = new BitmapFactory.Options();
// InPurgeable is used to free up memory while required
options.InPurgeable = true;
// Get the original image
using (var originalImage = BitmapFactory.DecodeByteArray(rawPhoto, 0, rawPhoto.Length, options))
{
// The shortest edge will determine the size of the square image
int cropSize = Math.Min(originalImage.Width, originalImage.Height);
int left = (originalImage.Width - cropSize) / 2;
int top = (originalImage.Height - cropSize) / 2;
using (var squareImage = Bitmap.CreateBitmap(originalImage, left, top, cropSize, cropSize))
{
// Resize the square image to the correct size of an Avatar
using (var resizedImage = Bitmap.CreateScaledBitmap(squareImage, outputSize, outputSize, true))
{
// Return the raw data of the resized image
using (MemoryStream resizedImageStream = new MemoryStream())
{
// Resize the image maintaining 100% quality
resizedImage.Compress(Bitmap.CompressFormat.Png, 100, resizedImageStream);
return resizedImageStream.ToArray();
}
}
}
}
}
iOS:
private const int BitsPerComponent = 8;
public byte[] ResizeImageAndCropToSquare(byte[] rawPhoto, int outputSize)
{
using (var data = NSData.FromArray(rawPhoto))
{
using (var photoToCrop = UIImage.LoadFromData(data).CGImage)
{
nint photoWidth = photoToCrop.Width;
nint photoHeight = photoToCrop.Height;
nint cropSize = photoWidth < photoHeight ? photoWidth : photoHeight;
nint left = (photoWidth - cropSize) / 2;
nint top = (photoHeight - cropSize) / 2;
// Crop image
using (var photoCropped = photoToCrop.WithImageInRect(new CGRect(left, top, cropSize, cropSize)))
{
using (var photoCroppedUIImage = UIImage.FromImage(photoCropped))
{
// Create a 24bit RGB image of output size
using (var cGBitmapContext = new CGBitmapContext(IntPtr.Zero, outputSize, outputSize, BitsPerComponent, outputSize << 2, CGColorSpace.CreateDeviceRGB(), CGImageAlphaInfo.PremultipliedFirst))
{
var photoOutputRectangleF = new RectangleF(0f, 0f, outputSize, outputSize);
// Draw the cropped photo resized
cGBitmapContext.DrawImage(photoOutputRectangleF, photoCroppedUIImage.CGImage);
// Get cropped resized photo
var photoOutputUIImage = UIImage.FromImage(cGBitmapContext.ToImage());
// Convert cropped resized photo to bytes and then stream
using (var photoOutputNsData = photoOutputUIImage.AsPNG())
{
var rawOutput = new byte[photoOutputNsData.Length];
Marshal.Copy(photoOutputNsData.Bytes, rawOutput, 0, Convert.ToInt32(photoOutputNsData.Length));
return rawOutput;
}
}
}
}
}
}
}
I have a cross platform app which I need to show a set of images when the user clic in a button, so, I put these image files named as "img000.png" to "img029.png" in a folder in the PCL solution and make al these images as "EmbeddedResource", after,I fill a List with all these images and its work fine at now, i.e. the image is shown like I want, but when I click in the button to show the next image in the list the image don't go to the next.
I have this:
//...
public class ImageSetPage : BasePage
// BasePage encapsule a ContentPage...
{
private string directory = "MyApp.Assets.";
private int idx = 0;
protected StackLayout _mainLayout;
protected StackLayout _buttonStack;
protected Image _btnPrevI;
protected Label _displayName;
protected Image _btnNestI;
protected Image _image;
protected List<Image> _Images;
public ImageSetPage()
{
this._Images = getImages();
var prevI_Tap = new TapGestureRecognizer();
prevI_Tap.Tapped += (s, e) =>
{
onClick("pvi");
};
var nextI_Tap = new TapGestureRecognizer();
nextI_Tap.Tapped += (s, e) =>
{
onClick("nti");
};
/// begin layout
base.Title = "set of Images";
this._mainLayout = new StackLayout()
{
Orientation = StackOrientation.Vertical,
BackgroundColor = Color.Black,
Padding = new Thickness(0, 10, 0, 0)
};
this._btnPrevI = new Image()
{
Aspect = Aspect.AspectFill,
Source = ImageSource.FromResource(directory+"prevbtn.png")
};
_btnPrevI.GestureRecognizers.Add(prevI_Tap);
this._displayName = new Label()
{
Style = Device.Styles.SubtitleStyle,
HorizontalOptions = LayoutOptions.CenterAndExpand,
VerticalOptions = LayoutOptions.CenterAndExpand,
TextColor = Color.White,
};
this._btnNextI = new Image()
{
Aspect = Aspect.AspectFill,
Source = ImageSource.FromResource(directory + "nextbtn.png")
};
_btnNextI.GestureRecognizers.Add(nextI_Tap);
this._buttonStack.Children.Add(_btnPrevI);
this._buttonStack.Children.Add(_displayName);
this._buttonStack.Children.Add(_btnNextI);
this._mainLayout.Children.Add(_buttonStack);
FillImage(idx);
this._mainLayout.Children.Add(this._image);
this.Content = this._mainLayout;
}
private void FillImage(int i)
{
this._displayName.Text = "Image n# " + FillWithZeroes(i);
// [EDIT 1] cemented these lines ...
// this._image = null;
// mi = _images[i];
// this._image = mi;
// [EDIT 2] the new try
string f = directory + "imgs.img0" + FillWithZeroes(i) + ".png";
this._image = new Image() {
VerticalOptions = LayoutOptions.Center,
Soruce = ImageSource.FromResource(f)
};
// In this way the image show and don't change when click
// this Fking* code is a big S_OF_THE_B*
// The Xamarin and the C# is brothers of this FKing* code
}
private void onClick(string v)
{
string vw = v;
if (vw.Equals("pvi")) idx--;
if (vw.Equals("nti")) idx++;
if (idx <= 0) idx = 29;
if (idx >= 29) idx = 0;
FillImage(idx);
vw = "";
}
private string FillWithZeroes(int v)
{
string s = v.ToString();
string r = "";
if (s.Length == 1) { r = "0" + s; } else { r = s; }
return r;
}
// to fill a list of Images with files in a PCL folder
private List<Image> getImages()
{
string directory = "MyApp.Assets.";
List<Image> imgCards = new List<Image>();
int c = 0;
for (c = 0; c < 30;c++) {
string f = directory + "imgs.img0" + FillWithZeroes(c) + ".png";
Image img = new Image();
img.Source = ImageSource.FromResource(f);
imgCards.Add(img);
}
return imgCards;
}
// ...
}
but the image don't change, i.e. change, like I see in debug, but don't show in the Layout when I click in the buttons.
Maybe I'm doing it wrong.
Can someone here help me?
thanks in advance
Can someone explain why part of my model flickers black when a material canvas material is added to it and when the camera moves?
Here's a shot of it before an image is added:
And after when an image has been added and camera rotated:
Notice the black marks at the top. Is this to do with the material I'm using possibly? Here's how I apply it:
for(let i = 0; i < sidesModified.length; i++) {
let sideName = sidesModified[i];
let side = this.getSideInLayersObservable(view, sideName);
let maxAnisotropy = (this.scene && this.scene['renderer']) ? this.scene['renderer'].getMaxAnisotropy() : 2;
let canvasTexture = new THREE.CanvasTexture(ctx.canvas, THREE.UVMapping, this.scene.materials.wrapS, this.scene.materials.wrapT, THREE.LinearFilter, THREE.LinearMipMapLinearFilter, THREE.RGBAFormat, THREE.UnsignedByteType, maxAnisotropy);
for(let j = 0; j < side.length; j++) {
canvasTexture.wrapS = this.scene.materials.wrapS;
canvasTexture.wrapT = this.scene.materials.wrapT;
this._reverseSideIf(this.sceneName, view, sideName, canvasTexture);
this._drawImageOnCtx(side, j, object, ctx);
}
let materialIndex = this.getMaterialIndexForBag(this.sceneName, view, sideName);
let material = this._setupMaterial(canvasTexture);
if(this.sceneName === 'two-d-scene') {
if(view === 'outside') {
this.selectedBag[0].children[materialIndex].material = material;
} else {
this.selectedBag[1].children[materialIndex].material = material;
}
} else {
this.selectedBag.children[materialIndex].material = material
}
canvasTexture.needsUpdate = true;
}
I am trying to create a pdf from listview items. This is my listview:
This is the result:
Below is my code:
ListView def = (ListView) findViewById(R.id.ist);
ListAdapter adapter = def.getAdapter();
int itemscount = adapter.getCount();
/*int itemsposition = adapter.getItem(position);*/
Toast.makeText(getApplicationContext(), itemscount + " temaxia", Toast.LENGTH_LONG).show();
int allitemsheight = 0;
List<Bitmap> bmps = new ArrayList<Bitmap>();
for (int i = 0; i < itemscount ; i++) {
View childView = adapter.getView(i, null, def);
/*View childView = def.getChildAt(1);*/
childView.measure(View.MeasureSpec.makeMeasureSpec(def.getWidth(),
View.MeasureSpec.EXACTLY),
View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));
childView.layout(0, 0, childView.getMeasuredWidth(),
childView.getMeasuredHeight());
childView.setDrawingCacheEnabled(true);
childView.buildDrawingCache();
childView.getDrawingCache();
/*bmps.add(childView.getDrawingCache());
allitemsheight+=childView.getMeasuredHeight();*/
Bitmap bigbitmap = Bitmap.createBitmap(def.getMeasuredWidth(),
childView.getMeasuredHeight(), Bitmap.Config.ARGB_8888);
Canvas bigcanvas = new Canvas(bigbitmap);
def.draw(bigcanvas);
Paint paint = new Paint();
bigcanvas.drawBitmap(bigbitmap,0,childView.getMeasuredHeight(),paint);
bigbitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);
Image myImg = Image.getInstance(stream.toByteArray());
myImg.scalePercent(45, 60);
myImg.setAlignment(Image.ALIGN_CENTER);
// add image to document
doc.add(myImg);
doc.add( new Paragraph());
}
I just cant find why it only gets childview in first position despite it is inside a for loop. Can anyone help me? Thanks.
I changed all the consept to: Create a big image from all childviews and then cut it to multiple pages A4 size.See below....NOTICE that first doc is never opened and never closed,but after creating image document is opened and closed properly ...............
File file = new File(dir, flname + ".pdf");
FileOutputStream fOut = new FileOutputStream(file);
FileOutputStream fOut2 = new FileOutputStream(file);
pdfWriter.getInstance(doc, fOut);
// open the document
/* doc.open();*/
ByteArrayOutputStream stream = new ByteArrayOutputStream();
//////////////////////
ListView def = (ListView) findViewById(R.id.ist);
ListAdapter adapter = def.getAdapter();
int itemscount = adapter.getCount();
/*int itemsposition = adapter.getItem(position);*/
Toast.makeText(getApplicationContext(), itemscount + " temaxia", Toast.LENGTH_LONG).show();
View childView =null;
int allitemsheight = 0;
List<Bitmap> bmps = new ArrayList<Bitmap>();
for (int i = 0; i < itemscount ; i++) {
childView = adapter.getView(i,null,def);
/*childView = def.getChildAt(i);*/
childView.measure(View.MeasureSpec.makeMeasureSpec(def.getWidth(),
View.MeasureSpec.EXACTLY),
View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));
childView.layout(0, 0, childView.getMeasuredWidth(),
childView.getMeasuredHeight());
childView.setDrawingCacheEnabled(true);
childView.buildDrawingCache();
/*childView.getDrawingCache();*/
bmps.add(childView.getDrawingCache());
allitemsheight+=childView.getMeasuredHeight();
}
Bitmap bigbitmap = Bitmap.createBitmap(def.getMeasuredWidth(),
allitemsheight , Bitmap.Config.ARGB_8888);
Paint paint = new Paint();
Canvas bigcanvas = new Canvas(bigbitmap);
for (int i = 0; i < bmps.size(); i++) {
Bitmap bmp = bmps.get(i);
bigcanvas.drawBitmap(bmp, 0, iHeight, paint);
/*bigcanvas.drawColor(Color.WHITE);
def.draw(bigcanvas);*/
iHeight+=bmp.getHeight();
bmp.recycle();
bmp=null;
}
bigbitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);
Image myImg = Image.getInstance(stream.toByteArray());
myImg.scalePercent(45, 60);
myImg.setAlignment(Image.ALIGN_CENTER);
/*if(myImg.getWidth() >= doc.getPageSize().getWidth() || myImg.getHeight() >= doc.getPageSize().getHeight()){
myImg.scaleToFit(doc.getPageSize());
doc.newPage();
}
myImg.setAbsolutePosition((doc.getPageSize().getWidth() - myImg.getScaledWidth()) / BaseField.BORDER_WIDTH_MEDIUM, (doc.getPageSize().getHeight() - myImg.getScaledHeight()) / BaseField.BORDER_WIDTH_MEDIUM);
doc.add(myImg);
doc.add( new Paragraph());*/
///////////////////////////////////////
/////////////////////////////////////////
/////////////////////////////////////
Document document = new Document();
PdfWriter pdfWriter2 = PdfWriter.getInstance(document, fOut2);
document.open();
PdfContentByte content = pdfWriter2.getDirectContent();
myImg.scaleAbsolute(PageSize.A4);
myImg.setAbsolutePosition(0, 0);
float width = PageSize.A4.getWidth();
float heightRatio = myImg.getHeight() * width / myImg.getWidth();
int nPages = (int) (heightRatio / PageSize.A4.getHeight());
float difference = heightRatio % PageSize.A4.getHeight();
while (nPages >= 0) {
document.newPage();
content.addImage(myImg, width, 0, 0, heightRatio, 0, -((--nPages * PageSize.A4.getHeight()) + difference));
}
document.close();
} catch (DocumentException de) {
Log.e("PDFCreator", "DocumentException:" + de);
} catch (IOException e) {
Log.e("PDFCreator", "ioException:" + e);
} finally {
/*doc.close();*/
}
My app need to load image from web each time with provided category and it is working, the problem is memory, Image loaded in memory not being remove when next category image load and hence memory increases and the app closing with the following message-
The program '[4036] TaskHost.exe' has exited with code -2005270523 (0x887a0005).
The code is ---
void webClient_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
{
if (e.Error != null)
{
timer.Stop();
return;
}
List rootobj = JsonConvert.DeserializeObject>(e.Result);
int c = 0, x = 0;
for (int i = 0; i < rootobj.Count; i++)
{
Image img = new Image();
img.HorizontalAlignment = System.Windows.HorizontalAlignment.Left;
img.VerticalAlignment = System.Windows.VerticalAlignment.Top;
img.Height = 160;
img.Width = 210;
img.Stretch = System.Windows.Media.Stretch.Fill;
BitmapImage bit = new BitmapImage();
string path = rootobj.ElementAt(i).ThumbnailUrl;
bit.UriSource = new Uri(path,UriKind.RelativeOrAbsolute);
img.Source = bit;
img.Margin = new Thickness(x, y, 0, 0);
c++;
if (c == 2)
{
x = 0;
y = y + 160;
c = 0;
}
else
{
x = x + 210;
}
mainGrid.Children.Add(img);
} mainGrid.Children.Add(grid);
}
and to remove i had tried these--
for (int i = 0; i < rootobj.Count; i++)
{
Image image = (Image)mainGrid.Children.ElementAt(i);
BitmapImage bitmapImage = image.Source as BitmapImage;
bitmapImage.UriSource = null;
image.Source = null;
bitmapImage = null;
image = null;
}
grid.Children.Clear();
mainGrid.Children.Remove(grid);
But it still crashes after few type of image selected.
you can do something like the following :
grid1.Children.Remove(image1);
image1 = null;