How to split an image into equal-sized parts? Just taking an image from asset and splitting it into equal parts in a grid-like manner, so that each image part can be used as a separate image.
Something similar to picture
You can use this package (https://pub.dev/packages/image) to crop the image from asset with the function copyCrop. Save them to List then display like your example.
Edit:
I think you know how to split your image and display them like your example if you know how to crop your image so I just show you how to change from image from asset to image of image package for cropping.
List<Image> splitImage(List<int> input) {
// convert image to image from image package
imglib.Image image = imglib.decodeImage(input);
int x = 0, y = 0;
int width = (image.width / 3).round();
int height = (image.height / 3).round();
// split image to parts
List<imglib.Image> parts = List<imglib.Image>();
for (int i = 0; i < 3; i++) {
for (int j = 0; j < 3; j++) {
parts.add(imglib.copyCrop(image, x, y, width, height));
x += width;
}
x = 0;
y += height;
}
// convert image from image package to Image Widget to display
List<Image> output = List<Image>();
for (var img in parts) {
output.add(Image.memory(imglib.encodeJpg(img)));
}
return output;
}
Remember to add this import 'package:image/image.dart' as imglib;
Related
I'm trying to create a histogram displaying the distances scanned by a Kinect vs. their occurrences. I've adapted the Histogram example code to create a depth histogram, but it's currently displaying the depth at each pixel (from left to right) multiple times across the depth image width.
What I'm looking to do is reorder the depth information so that it ranges from the lowest value (that isn't 0) to the highest on the x axis, and shows their occurrences on the y. I'm using Processing, so I'm unsure if this is the right site to be posting on, but I've tried on the posting forum and not gotten any help. If anyone can show me where I'm going wrong, that'd be awesome. My current code is below, and a screenshot of my current output can be found here
import SimpleOpenNI.*;
SimpleOpenNI kinect;
void setup() {
size(1200, 580);
kinect = new SimpleOpenNI(this);
kinect.enableDepth();
}
void draw () {
kinect.update();
PImage depthImage = kinect.depthImage();
image (depthImage, 11, 0);
int[] depthValues = kinect.depthMap();
int[] hist = new int[716800];
for (int x = 11; x < depthImage.width; x++) {
for (int y = 0; y < depthImage.height; y++) {
int i = x + y * 640;
hist[i] = depthValues[i];
}
}
int histMax = max(hist);
stroke(20);
for (int i = 0; i < depthImage.width; i += 2) {
int which = int(map(i, 0, depthImage.width, 0, histMax));
int y = int(map(hist[which], 0, histMax, depthImage.height, 0));
line(i, depthImage.height, i, y);
}
}
I think you're asking two questions here.
How to get the histogram to go from 0-N:
Use Processing's sort() function to sort the array.
hist = sort(hist); // sorts your array numerically
How to get the histogram to fill the screen:
I'm not entirely sure why it's drawing twice, but I think you can clean up your code quite a bit.
// how far apart are the bars - set based on screen dimensions
int barSpacing = width / hist.length;
for (int i=0; i<hist.length; i++) {
// get value and map into usable range (note 10 not 0 for min)
int h = int(map(hist[i], 0,histMax, 10,height));
// set x position onscreen
int x = i * barSpacing;
// draw the bar
line(x,height, x,height-h);
}
I am new to DirectX and trying to use SharpDX to capture a screen shot using the Desktop Duplication API.
I am wondering if there is any easy way to create bitmap that I can use in CPU (i.e. save on file, etc.)
I am using the following code the get the desktop screen shot:
var factory = new SharpDX.DXGI.Factory1();
var adapter = factory.Adapters1[0];
var output = adapter.Outputs[0];
var device = new SharpDX.Direct3D11.Device(SharpDX.Direct3D.DriverType.Hardware,
DeviceCreationFlags.BgraSupport |
DeviceCreationFlags.Debug);
var dev1 = device.QueryInterface<SharpDX.DXGI.Device1>();
var output1 = output.QueryInterface<Output1>();
var duplication = output1.DuplicateOutput(dev1);
OutputDuplicateFrameInformation frameInfo;
SharpDX.DXGI.Resource desktopResource;
duplication.AcquireNextFrame(50, out frameInfo, out desktopResource);
var desktopSurface = desktopResource.QueryInterface<Surface>();
can anyone please give me some idea on how can I create a bitmap object from the desktopSurface (DXGI.Surface instance)?
I've just completed this myself although I am not going to say much about this code!
public byte[] GetScreenData()
{
// We want to copy the texture from the back buffer so
// we don't hog it.
Texture2DDescription desc = BackBuffer.Description;
desc.CpuAccessFlags = CpuAccessFlags.Read;
desc.Usage = ResourceUsage.Staging;
desc.OptionFlags = ResourceOptionFlags.None;
desc.BindFlags = BindFlags.None;
byte[] data = null;
using (var texture = new Texture2D(DeviceDirect3D, desc))
{
DeviceContextDirect3D.CopyResource(BackBuffer, texture);
using (Surface surface = texture.QueryInterface<Surface>())
{
DataStream dataStream;
var map = surface.Map(SharpDX.DXGI.MapFlags.Read, out dataStream);
int lines = (int)(dataStream.Length / map.Pitch);
data = new byte[surface.Description.Width * surface.Description.Height * 4];
int dataCounter = 0;
// width of the surface - 4 bytes per pixel.
int actualWidth = surface.Description.Width * 4;
for (int y = 0; y < lines; y++)
{
for (int x = 0; x < map.Pitch; x++)
{
if (x < actualWidth)
{
data[dataCounter++] = dataStream.Read<byte>();
}
else
{
dataStream.Read<byte>();
}
}
}
dataStream.Dispose();
surface.Unmap();
}
}
return data;
}
This will get you a byte[] which can then be used to generate a bitmap.
The following is how I saved to a png Image.
using (var stream = await file.OpenAsync( Windows.Storage.FileAccessMode.ReadWrite ))
{
BitmapEncoder encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.PngEncoderId, stream);
double dpi = DisplayProperties.LogicalDpi;
encoder.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Straight,
(uint)width, (uint)height, dpi, dpi, pixelData);
encoder.BitmapTransform.ScaledWidth = (uint)newWidth;
encoder.BitmapTransform.ScaledHeight = (uint)newHeight;
await encoder.FlushAsync();
waiter.Set();
}
I know this was answered a while ago, and maybe you figured it out by now :3 but if someone else gets stuck I hope this helps!
The MSDN page for the Desktop Duplication API tells us the format of the image:
DXGI provides a surface that contains a current desktop image through the new IDXGIOutputDuplication::AcquireNextFrame method. The format of the desktop image is always DXGI_FORMAT_B8G8R8A8_UNORM no matter what the current display mode is.
You can use the Surface.Map(MapFlags, out DataStream) method get access to the data on the CPU.
The code should look like* this:
DataStream dataStream;
desktopSurface.Map(MapFlags.Read, out dataStream);
for(int y = 0; y < surface.Description.Width; y++) {
for(int x = 0; x < surface.Description.Height; x++) {
// read DXGI_FORMAT_B8G8R8A8_UNORM pixel:
byte b = dataStream.Read<byte>();
byte g = dataStream.Read<byte>();
byte r = dataStream.Read<byte>();
byte a = dataStream.Read<byte>();
// color (r, g, b, a) and pixel position (x, y) are available
// TODO: write to bitmap or process otherwise
}
}
desktopSurface.Unmap();
*Disclaimer: I don't have a Windows 8 installation at hand, I'm only following the documentation. I hope this works :)
Lets say I have 100 one-colored A4 sheets of paper, that are cut into different shapes and figures (2D), scanned, saved as an image file, and then needs to be sorted in ascending order of area.
Is there an effective way to find the area of the figures and arrange them?
If all pictures have the same size and all shapes the same color (that´s the situation if I don´t missunderstand your question), you can calculate the average color value.
The nearer the calculated color comes to the figures´s color, the bigger is the shape on the Image.
Some code:
private Color GetAverageImageColor(Image img)
{
double[] rgb = new double[3];
Color col;
Bitmap bmp = new Bitmap(img);
for(int y = 0; y < bmp.Size.Height; y++)
{
for(int x = 0; x < bmp.Size.Width; x++)
{
col = bmp.GetPixel(x, y);
rgb[0] += col.R;
rgb[1] += col.G;
rgb[2] += col.B;
}
}
for (int i = 0; i < 3; i++)
{
rgb[i] /= (bmp.Size.Height * bmp.Size.Width);
rgb[i] = Math.Round(rgb[i]);
}
return Color.FromArgb((int) rgb[0], (int) rgb[1], (int) rgb[2]);
}
I'm currently making an application using processing intended to take an image and apply 8bit style processing to it: that is to make it look pixelated. To do this it has a method that take a style and window size as parameters (style is the shape in which the window is to be displayed - rect, ellipse, cross etc, and window size is a number between 1-10 squared) - to produce results similar to the iphone app pxl ( http://itunes.apple.com/us/app/pxl./id499620829?mt=8 ). This method then counts through the image's pixels, window by window averages the colour of the window and displays a rect(or which every shape/style chosen) at the equivalent space on the other side of the sketch window (the sketch when run is supposed to display the original image on the left mirror it with the processed version on the right).
The problem Im having is when drawing the averaged colour rects, the order in which they display becomes skewed..
Although the results are rather amusing, they are not what I want. Here the code:
//=========================================================
// GLOBAL VARIABLES
//=========================================================
PImage img;
public int avR, avG, avB;
private final int BLOCKS = 0, DOTS = 1, VERTICAL_CROSSES = 2, HORIZONTAL_CROSSES = 3;
public sRGB styleColour;
//=========================================================
// METHODS FOR AVERAGING WINDOW COLOURS, CREATING AN
// 8 BIT REPRESENTATION OF THE IMAGE AND LOADING AN
// IMAGE
//=========================================================
public sRGB averageWindowColour(color [] c){
// RGB Variables
float r = 0;
float g = 0;
float b = 0;
// Iterator
int i = 0;
int sizeOfWindow = c.length;
// Count through the window's pixels, store the
// red, green and blue values in the RGB variables
// and sum them into the average variables
for(i = 0; i < c.length; i++){
r = red (c[i]);
g = green(c[i]);
b = blue (c[i]);
avR += r;
avG += g;
avB += b;
}
// Divide the sum of the red, green and blue
// values by the number of pixels in the window
// to obtain the average
avR = avR / sizeOfWindow;
avG = avG / sizeOfWindow;
avB = avB / sizeOfWindow;
// Return the colour
return new sRGB(avR,avG,avB);
}
public void eightBitIT(int style, int windowSize){
img.loadPixels();
for(int wx = 0; wx < img.width; wx += (sqrt(windowSize))){
for(int wy = 0; wy < img.height; wy += (sqrt(windowSize))){
color [] tempCols = new color[windowSize];
int i = 0;
for(int x = 0; x < (sqrt(windowSize)); x ++){
for(int y = 0; y < (sqrt(windowSize)); y ++){
int loc = (wx+x) + (y+wy)*(img.width-windowSize);
tempCols[i] = img.pixels[loc];
// println("Window loc X: "+(wx+(img.width+5))+" Window loc Y: "+(wy+5)+" Window pix X: "+x+" Window Pix Y: "+y);
i++;
}
}
//this is ment to be in a switch test (0 = rect, 1 ellipse etc)
styleColour = new sRGB(averageWindowColour(tempCols));
//println("R: "+ red(styleColour.returnColourScaled())+" G: "+green(styleColour.returnColourScaled())+" B: "+blue(styleColour.returnColourScaled()));
rectMode(CORNER);
noStroke();
fill(styleColour.returnColourScaled());
//println("Rect Loc X: "+(wx+(img.width+5))+" Y: "+(wy+5));
ellipse(wx+(img.width+5),wy+5,sqrt(windowSize),sqrt(windowSize));
}
}
}
public PImage load(String s){
PImage temp = loadImage(s);
temp.resize(600,470);
return temp;
}
void setup(){
background(0);
// Load the image and set size of screen to its size*2 + the borders
// and display the image.
img = loadImage("oscilloscope.jpg");
size(img.width*2+15,(img.height+10));
frameRate(25);
image(img,5,5);
// Draw the borders
strokeWeight(5);
stroke(255);
rectMode(CORNERS);
noFill();
rect(2.5,2.5,img.width+3,height-3);
rect(img.width+2.5,2.5,width-3,height-3);
stroke(255,0,0);
strokeWeight(1);
rect(5,5,9,9); //window example
// process the image
eightBitIT(BLOCKS, 16);
}
void draw(){
//eightBitIT(BLOCKS, 4);
//println("X: "+mouseX+" Y: "+mouseY);
}
This has been bugging me for a while now as I can't see where in my code im offsetting the coordinates so they display like this. I know its probably something very trivial but I can seem to work it out. If anyone can spot why this skewed reordering is happening i would be much obliged as i have quite a lot of other ideas i want to implement and this is holding me back...
Thanks,
In the program below, I try to change the pixel colors form a image with the click of the mouse, however, I'm trying to return to the original image with the second click but I haven't been able to find the rigth argument to do it...
PImage pic;
void setup(){
pic=loadImage("road.jpg"); // Loading the image from a folder "date" attached to the sketch
size (pic.width,pic.height);
image(pic,0,0);
}
void draw(){
}
void mousePressed(){
loadPixels();
pic.loadPixels();
for (int y = 0; y < height; y++ ) {
for (int x = 0; x < width; x++ ) {
int loc = x + y*width;
if(red(pixels[loc]) >170 && red(pixels[loc])<215){
pixels[loc]=color(187,0,0); //changing the pixels color from red to green
}
}
}
for (int y = 0; y < height; y++ ) {
for (int x = 0; x < width; x++ ) {
int loc = x + y*width;
if(green(pixels[loc]) >120 && green(pixels[loc])<160){
pixels[loc]=color(0,192,0); //changing the pixels color form green to red
}
}
}
// I belive that here I have to add an argument that returns to the original image
updatePixels();
}
I will appreciate any help.
Thanks.
What I typically do for this sort of thing is to create /two/ images, one being the file (target) and the other being a blank Image.
PImage target;
PImage destination;
target = loadImage("file.jpg");
destination = createImage(target.width, target.height, RGB);
And then I copy the target's information into the destination's pixels. If I want to switch back, I can just call target; I'm able to freely swap back and forth by saving them as two separate images.
For an example, check out a sketch of mine on openprocesing: http://openprocessing.org/visuals/?visualID=49301