I'm using vtkTexturedActor2D and vtkImageMapper to display a 2D image. I can use
actor.GetPositionCoordinate().SetCoordinateSystemToNormalizedDisplay();
actor.this.Actor.SetPosition(0.5, 0.9);
to place the image in the center of the window, but it's not center-aligned. The corner of the image is placed in the center. How can I center-align the image so that the center of the image is at the center of the window?
I had this same problem.
This seems to solve it:
float height, width;
this->d_actor->GetPositionCoordinate()->SetCoordinateSystemToNormalizedViewport();
this->d_actor->GetPositionCoordinate()->SetViewport(this); // Without this was getting weird results
height = this->d_actor->GetHeight();
width = this->d_actor->GetWidth();
this->d_actor->GetPositionCoordinate()->SetValue(.5 - width/2.0, .5 - height/2.0);
Related
I have one pdf file and one image file which is the signature of the client. I need to place the client signature image on the top right corner of every page of pdf. This whole process is in node js so I have used the pdf-lib npm package to attach image on pdf. The current issue I'm unable to place the image on the top-right corner.
Below is the logic which I used to set an image on the top-right corner of the pdf but this logic is not true for every case in some cases when the width of the image or pdf changes then it's not worked as expected. Sometimes images are getting too much small or sometimes too much large.Just because I set fix height and width. As I don't know how to calculate it dynamically
const pages = pdfDoc.getPages();
for (let i = 0; i < pdfDoc.getPageCount(); i++) {
let imagePage='';
imagePage = pdfDoc.getPage(i);
console.log(i+1)
console.log(imagePage.getWidth())
let xx=imagePage.getWidth()
console.log(imagePage.getHeight())
console.log(img.width)
console.log(img.height)
let yy=imagePage.getHeight()
imagePage.drawImage(img, {
x: xx-150,
y: yy-70,
width: 70,
height: 70
})
}
Please check console values below
595.5 at imagePage.getWidth()
842.2499787 at imagePage.getHeight()
1200 at img.width
700 at img.height
please check the above image where I attached the signature to pdf but in this case, the signature image is not properly visible so how can I set the image to pdf on the top-right corner?
How can I calculate the x and y position dynamically for any pdf?
I got the solution to get dynamic x and y values to set an image on the top-right corner of the pdf
let xx=imagePage.getWidth();
console.log(imagePage.getHeight());
console.log("[PAGE_HEIGHT]",imagePage.getHeight());
const imgHeight = img.height;
const imgWidth = img.width;
console.log("[SIGNATURE_IMAGE_WIDTH]",img.width);
console.log("[SIGNATURE_IMAGE_HEIGHT]",img.height);
const marginX = 50;
let yy=imagePage.getHeight();
imagePage.drawImage(img, {
x: xx -marginX-imgWidth,
y: yy- marginX-imgHeight,
width: imgWidth,
height: imgHeight
})
margin is a fixed value to move an image from the top and right sides to get a proper view.
I have removed image height and width from the actual page width and height that will return top right corner.
Recently I'm learning skia library(google open source 2d engine,be used on Android and chromium,etc.),Now I want to use it on windows instead of GDI+ dont support clip area with antialias,during it, I find a problem about pixel.
up is set antialias,down is not set antialias
the main code is:
paint.setStrokeWidth(1);
paint.setStyle(SkPaint::kStroke_Style);
paint.setAntiAlias(true);
canvas.drawRect(skrect,paint); //draw up rect
skrect.fTop += 110;
skrect.fBottom += 110;
paint.setAntiAlias(false);
canvas.drawRect(skrect, paint); //draw down rect
As you see,the same rect,if I not set Antialias,the boundary pixel is 1(I set strock width is 1),but if I set Antialias, the boundary pixel is 2,and it become a bit light,although I set color is black.
I dont konw why,anyone can tell me?
thk,
now,maybe I konw.
the skia library canvas should be like Html5`s canvas ,Canvas every line have an infinite thin "line", the width of the line from the center line to stretch,so if we draw a 1px line,in fact,it will fill two of 0.5 pixel point,but the display device dont allow it do that,so it will fill 2 pixel point,and set it color more light to differentiate real 2 pixels .
I will search more material to prove it.
This happens because OpenGL assumes that each pixel is centered at [0.5; 0.5]. The rasterizer have to draw indeed two pixels and interpolate the alpha. Read more here
If you would like to draw sharp 1px lines with antialiasing turned on just offset coordinates of a line or other figure with 0.5f.
For example a point at [10; 10] should have coordinates [10.5; 10.5] and so on
I have a mat object, which has image information used by openCV library for image processing. The mat object is basically a matrix. I need to scale this object to the size of the linear layout in which i need to display after converting it to Bitmap.
The steps would briefly be as follows:-
1. Get the height and width of the linear layout.
2. Scale the mat object to the width and height.
3. Convert the object to bitmap
4. Display the bitmap onto the linear layout
I do all this in the onStart method where the layout with and height is 0. I am failing in the first step.
How do i get the width and height.
Also Can i get the coordinates of the linear layout in onstart() method.
Kindly help
Crazy idea would be to display a dummy image first, get the layout width and height and then display the actual image....i am a beginner...
Rather do it the other way,as shown below -
i> Convert the Mat image to BitMap. Here is the code for doing so -
Mat mat;
// Intialize mat
Bitmap bitMap = Bitmap.createBitmap(mat.cols(), mat.rows(),Bitmap.Config.ARGB_8888);
Utils.matToBitmap(mat, bitMap);
ii> In the layout file, use an ImageView in the LineatLayout and set the layout_width and fill_height to match_parent. This will use the whole linear layout. Here is the code for doing so -
<ImageView
android:id="#+id/image_view"
android:contentDescription="#string/description"
android:layout_width= "match_parent"
android:layout_height="match_parent" />
Don't forget to add description in strings.xml.
iii> Put the Bitmap image in the LinearLayout, as shown below -
ImageView imageView = (ImageView) findViewById(R.id.image_view);
imageView.setImageBitmap(bitMap);
Using this code, you will be able to display a Mat image in a LinearLayout.
In my j2me App I have tried canvas which works great on Nokia phone but doesn't run on samsung. For that I have to switch to some FORM which in both cases works but only issue is of size, if I create smaller image to fit for both phone screens, one (samsung) shows that ok but other (nokia) leaves a lot more space and vice versa.
I need to have code that could stretch my image and just fix if to the screen size which I basically get by form.getHeight() and form.getWidth() property. I wonder if there is property of Image.createImage(width, height) then why doesn't it stretch it to the value I provide?
my code for that is below
try {
System.out.println("Height: " + displayForm.getHeight());
System.out.println("Width: " + displayForm.getWidth());
Image img1 = Image.createImage("/bur/splashScreen1.PNG");
img1.createImage(displayForm.getHeight(), displayForm.getWidth());
displayForm.append(new ImageItem(null, img1, Item.LAYOUT_CENTER, null));
} catch (Exception ex) {
}
Image
A single image will not fit all screens. But more will do.
The smaller logo image should be less than 96x54, as this is the smallest screen resolution. This image can be used up to the resolution of 128x128 without problems. With bigger resolutions it will look tiny, though.
The bigger logo image should be a bit bigger than 128x128 and can be used up to 240x320.
The code bellow gives as example of how to implement this.
import javax.microedition.lcdui.Image;
import javax.microedition.lcdui.Graphics;
class Splash extends javax.microedition.lcdui.Canvas {
Image logo;
Splash () {
if (getWidth() <= 128) {
// sl stands for Small Logo and does not need to have a file extension
// this will use less space on the jar file
logo = Image.createImage("/sl");
} else {
// bl stands for Big Logo
logo = Image.createImage("/bl");
}
}
protected void paint (Graphics g) {
// With these anchors your logo image will be drawn on the center of the screen.
g.drawImage(logo, getWidth()/2, getHeight()/2, Graphics.HCENTER | Graphics.VCENTER);
}
}
As seen in http://smallandadaptive.blogspot.com.br/2008/10/showing-splash.html
wonder if there is property of Image.createImage(width, height) then why doesn't it stretch it to the value I provide?
Parameters in this method have nothing to do with stretching, see API javadocs:
public static Image createImage(int width, int height)
Creates a new, mutable image for off-screen drawing.
Every pixel within the newly created image is white.
The width and height of the image must both be greater than zero.
Parameters:
width - the width of the new image, in pixels
height - the height of the new image, in pixels
Image class (API javadocs) has two more createImage methods that use parameters called "width" and "height" - one with six, another with four arguments but none of these has anything to do with stretching.
In createImage with six arguments, width and height specify size of the region to be copied (without stretching) from source image.
In method with four arguments, width and height specify how to interpret source ARGB array, without these it would be impossible to find out if, say, array of 12 values represents 3x4 image or 4x3. Again, this has nothing to do with stretching.
This may be a very dumb question, but how do I draw a path that will stretch to a div's width?
I am experimenting with Raphaeljs to make an interactive chart: the user can click sparklines and the lines shift up and down to reveal text content. I see that Raphael's rectangles and other shapes will stretch to width fine by setting the width to 100%, but I can't get a line to do this.
I've set up the paper like this:
var SLAPaper = new Raphael( document.getElementById("LineSLA"), "100%", 60);
Set up the line like this:
var lineSLA = SLAPaper.path("F1 M 0,42L 103,12L 222,45L 390,13L 460,45L 453,27L 455,28L 450,0L 479,25");
I also set a viewbox but this doesn't seem to make a difference. I can't set a % width on the viewbox anyway:
SLAPaper.setViewBox(0,0,1500,60, true);
Any help appreciated. Thanks.
I've personally had problems with using percentages for defining size of both paper and objects in Raphael, especially with Internet Explorer. The best I could come up with would be to scale the line to fit inside paper, based on the width of the path (assuming that the width is more than the height):
var line = SLAPaper.path("F1 M 0,42L 103,12L 222,45L 390,13L 460,45L 453,27L 455,28L 450,0L 479,25");
var scl = SLAPaper.width / line.getBBox().width;
line.transform('S' + scl + ',' + scl + ',0,0');