Processing Forum

copy and resize part of image

[2 Replies]
- 02-Aug-2013 07:00 AM
- Forum: General Discussion
Hi,

how do I copy and resize a part of an image to another Image?

I would like to do the same the copy() function does:
```
copy(src, sx, sy, sw, sh, dx, dy, dw, dh)
```
```
But the result should end up in an PImage, not on the screen.
```
```
Thanks lot Robert
```

rotate shape

[4 Replies]
- 22-Jul-2013 06:58 AM
- Forum: Programming Questions
Hi,

I try to rotate a shape. The shape is a rect which is supposed to stay in the middle of the 500x500 (second window with map) screen.
It should turn to "theta" (variable submitted from my robot).

But when it rotates, it significantly moves away from the center.

What do I do wrong?

My code:
1. void setup(){
2. Robot = createShape(RECT, 0, 0, 20, 16);
3. Robot.setFill(255);
4. }
6. void draw(){
7. Robot.resetMatrix();
8. Robot.rotate(-theta);
9. Robot.translate(240,242);
10. Map.papplet.shape(Robot);
11. }
Thanks
Robert

cartesian coordinates shift/offset

[2 Replies]
- 18-Jul-2013 11:54 PM
- Forum: General Discussion
Hi,

I use processing for visualizing sensor readings of my robot. The sensors are not at the center of the robot. So I need to add some shift/offset to the readings.

I have X,Y and theta of the robot. I know the offset of the sensors from the center of the robot.

--> Is there a simple formula to calculate the X/Y position of the sensor based on the current robot position and heading?

I could of cause do something like “90 degree right + X offset -> 90 degree left + Y offset”. But this would require quite some calculations per sensor data point.
There must be a simpler mathematical solution.

Thanks
Robert

PImage / pixels[]

[6 Replies]
- 04-Apr-2013 03:55 AM
- Forum: Programming Questions
Hi.

Because of this problem: redraw problem

I want to use a pimage instead of drawing points.

But again .. strange things happen. I expect a 500x500 picture. But it looks line the screen below.

Here the relevant code:
1. PImage MapIMG = createImage(500,500,RGB);
drawMap() ist called in the main loop.
1. void drawMap() {
2. loadPixels();
3. int counter=0;
5. for (int x=0; x < MapIMG.height;x++) {
6. for (int y=0; y < MapIMG.width;y++) {
7. color c = color(map[x][y]);
8. pixels[x + y*MapIMG.width] = c;
9. }
10. }
11. updatePixels();
12. image(MapIMG,0,0);
13. }
That's not 500*500 and always only the top of the image :-/ (screenshot only from the top of the screen)

Again .. can't be this hard. But I don't get it. Where am I wrong?

A bit frustrating now :-)

Thanks

Robert

redraw map - I don't find the mistake

[4 Replies]
- 03-Apr-2013 05:38 AM
- Forum: Programming Questions
Hi,

I draw a map (for debugging reasons it now has a color gradient).

When I try to redraw a part of it, the picture is wrong. I don't find my mistake.

Maybe I am blind ...

I generate the map like this:
1. void initializeMap() {
2. for (int x=0;x<Size;x++) {
3. for (int y=0;y<Size;y++) {
4. if ((x % 20) == 0 || (y % 20) == 0) map[x][y] = int(50 + x/2.5) ;
5. else map[x][y] = 0;
6. }
7. }
8. }
I draw the map like this (size is the size of the array/map - mapX and mapY are the offset on the screen):
1. void drawMap() {
2. if (newcoord == true) {
3. for (int x=0;x<Size;x++) {
4. for (int y=0;y<Size;y++) {
5. stroke(map[x][y]);
6. point(x+mapX, y+mapY);
7. }
8. }
9. }
10. }
I redraw like this (just a simplified test for now - the usecase will be more complicated):

The only change to the draw map (which works) is that I don't query the whole array. " for (int x=100" instead of " for (int x=0"
1. void deleteRobot() {
2. for (int x=100;x<Size;x++) {
3. for (int y=0;y<Size;y++) {
4. stroke(map[x][y]);
5. point(x+mapX, y+mapY);
6. }
7. }
8. }
The correct map:

Wrong ater partial redraw:

I hope you see the error. Must be something stupid.

Thanks

Robert

[solved] G4P textarea.append doesn't redraw

[4 Replies]
- 19-Feb-2013 12:17 AM
- Forum: Contributed Library Questions
Hi,

I use G4P for my GUI.

to log messages I add the last message with textarea.append(String).

It works beside that the messages only show once I use another opbject live a checkbox.

I tried textarea.draw() but this doesn't force a readraw.

How do I get the textarea to update?

Thanks

Robert

2nd window with different or no framerate

[1 Reply]
- 01-Feb-2013 04:42 AM
- Forum: Contributed Library Questions
Hi,

I use G4P for my main GUI. I now would like to have a 2nd window, which G4P provides as feature.

What I would like to achive:

- no (automatic) redraw of the 2nd Window (as I want to paint a mojor pixel map, where painting it for every from the data array is too heavy)

- access Data from the initial window/thread (or manipulate data of the 2nd window from within the main program)

Is this achievable?

I want to work around my main issue descibed here:

https://forum.processing.org/topic/map-for-robot-good-approach#25080000001964045

Thanks

Robert

Map for Robot - good approach?

[3 Replies]
- 22-Jan-2013 01:11 AM
- Forum: General Discussion
Hi,
I am building a program for steering my robot and mapping the environment.
My question is about drawing and storing the map.

What I want:
- 1cm resolution
- 10x10 meter map size (or dynamically expanding if possible)
- rotatable and zoomable
My approach would be to create a 1000x1000 byte array (store not scanned, clear, blocked).
If I want to rotate the map, I need to recalculate position of each pixel.

If I zoom I read only a smaller portion of the array and draw dots with arrayvalue*zoom in size.

I store the map in a csv (all array values). I could also store only scanned points. But as I would need store position, the amount of date would be equal or even more.

Is this the best or at least a good approach? Does someone has tips or a demo project?

Thanks
Robert

deleting part of the screen

[4 Replies]
- 17-Jan-2013 02:57 AM
- Forum: General Discussion
Hi,

I need some help regarding redrawing only part of the screen.

On the screen I draw point (from a measurement). In addition I write some text about statistics.

I now want to change the text (based on changed values) but I don't want to delete the points.

So I can't use background() in the draw() function.

I don't want to buffer the point values and redraw them every time.

Alternatively I could draw a retangle above the text. Also not very elegant.

Is there a better option?

Thanks

Robert

Library for manipulating a PImage

[8 Replies]
- 11-Jan-2013 05:12 AM
- Forum: Contributed Library Questions
Hi,

I would like to manipulate (sharpen, contrast, brightness) a Pimage.

Is there a library for this? I found imageadjuster. But this seems to not work with PImage and it doesn't contain sharpening as effect.

Thanks

Robert

Writing pixels to a pimage (positioning pixels right)

[3 Replies]
- 09-Jan-2013 11:33 PM
- Forum: Programming Questions
Hi,

I am trying to display an image I receive via serial. I submit different color depths.

The code is below reacts on:

g_grayscaleImage == 0     // 16 bit rgb
g_grayscaleImage == 1     // 8 bit grayscale
g_grayscaleImage == 2     // 4 bit grayscale

The code works fine for 16 and 8 bit. With 4 bit I don’t get the pixels to the right position. (so the part from "else if (g_grayscaleImage==2)" doesn't work)

The “best” result I got with the code below. It looks like this:
http://www3.picturepush.com/photo/a/11925461/img/11925461.jpg

Does someone see the mistake and can help me out?

Here the code:
1. for (int row = imageh-1; row >= 0; --row)
2. {
3. for (int col = 0; col < imagew; ++col)
4. {
5. int loc = imagew*row+col;
6. if (g_grayscaleImage==0) {
7. int msb = packedbuf[2*loc] & 0xff;
8. int lsb = packedbuf[2*loc+1] & 0xff;
9. int r = (lsb >>> 3);
10. int g = ((lsb & 0x7) << 3);
11. g |= (msb >>> 5);
12. int b = (msb & 0x1f);
14. r = (r << 3)|(r >>> 2);
15. g = (g << 2)|(g >>> 4);
16. b = (b << 3)|(b >>> 2);
17. img.pixels[loc] = color(r, g, b);
18. }
19. else if (g_grayscaleImage==1) {
20. img.pixels[loc] = color(packedbuf[loc], packedbuf[loc], packedbuf[loc]);
21. }
22. else if (g_grayscaleImage==2) {
23. int LeftPixel = packedbuf[loc/2] & 0XF0;
24. int RightPixel = packedbuf[loc/2] << 4;
26. img.pixels[loc] = color(LeftPixel, LeftPixel, LeftPixel);
27. img.pixels[loc+1] = color(RightPixel, RightPixel, RightPixel);
28. ++col;
29. }
30. }
31. }
33. img.updatePixels();
34. return img;
35. }
Thanks
Robert

redefine 2D array content

[5 Replies]
- 27-Sep-2012 08:11 AM
- Forum: Programming Questions
Hi,

I am struggeling with the following:

I define two 2D arrays ( GaitSTOP & GaitFWD) as values for a container array Gait1:
2. int GaitSTOP[][]= {
3. { O1C, U1C, O2C, U2C, O3C, U3C, O4C, U4C, 200}
4. };
6. int GaitFWD[][]= {
7. { O1H, U1C, O2C, U2O, O3C, U3C, O4H, U4O, 200},
8. { O1H, U1C, O2C, U2C, O3C, U3C, O4H, U4C, 200},
9. { O1C, U1O, O2H+10, U2C, O3H-5, U3O, O4C, U4C, 200}
10. };
12. int Gait1[][]=GaitSTOP;
I now want to change the content on Gait1 during runtime between the two other arrays.

I do it like this:
1. Gait1[][]=GaitFWD;
and
1. Gait1[][]=GaitSTOP;
But the content doesn't seem to change.

What is the correct way to replace the complete content for an array?

Thanks

Robert

arduino+bluetooth<->Bluetooth-Android-WLAN<->WLAN-PC

[2 Replies]
- 04-Jul-2012 11:12 PM
- Forum: Integration and Hardware
Hi,

can someone please be so kind to get me started on the following topc:

What I have:

- Arduino Board with bluetooth module

- Android mobile

- Windows PC

What I would like to do:

Steer the Arduino board though a graphical interface from my PC.

The comminucation from PC to the Android mobile should be established via WLAN.

The Android mobile and the arduino board can comminucate via Bluetooth.

What is the best way to do this? Is it possible with processing at all?

Thanks

Robert

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