DZone Snippets: zoom code

Using the mousewheel to zoom in or out an SVG document

jrobertson (James Robertson) — Tue, 08 Apr 2008 16:14:22 GMT

This code was originally copied from Mouse wheel programming in JavaScript [adomas.org]. I replaced about 5 lines of code to get the mousewheel controlling the zoom feature in the makeZoom.svg [dzone.com] file.



  /** This is high-level function; REPLACE IT WITH YOUR CODE.

 * It must react to delta being more/less than zero.

 */

function zoomInOut(delta) {

	if (delta >= 0)

		zoomIn()

	else

		zoomOut()

}



function wheel(event){

	var delta = 0;

	if (!event) event = window.event;

	if (event.wheelDelta) {

		delta = event.wheelDelta/120; 

		if (window.opera) delta = -delta;

	} else if (event.detail) {

		delta = -event.detail/3;

	}

	if (delta)

		zoomInOut(delta);

        if (event.preventDefault)

                event.preventDefault();

        event.returnValue = false;

}



/* Initialization code. */

if (window.addEventListener)

	window.addEventListener('DOMMouseScroll', wheel, false);

window.onmousewheel = document.onmousewheel = wheel;

Java - ZoomOUT image

whitetiger () — Mon, 30 Oct 2006 03:03:40 GMT



public BufferedImage zoomOut(BufferedImage bi, int scale)

	{

		int width = bi.getWidth() / scale;

		int height = bi.getHeight() / scale;

		

		BufferedImage biScale = new BufferedImage(width, height, bi.getType());

		

		for(int i=0; i			for(int j=0; j				biScale.setRGB(i, j, bi.getRGB(i*scale, j*scale));

		

		return biScale;

	}

Java - ZoomIN Image

whitetiger () — Mon, 30 Oct 2006 02:49:55 GMT



public BufferedImage zoomIn(BufferedImage bi, int scale)

	{

		int width = scale * bi.getWidth();

		int height = scale * bi.getHeight();

		

		BufferedImage biScale = new BufferedImage(width, height, bi.getType());

		

                // Cicla dando un valore medio al pixel corrispondente

		for(int i=0; i			for(int j=0; j				biScale.setRGB(i, j, bi.getRGB(i/scale, j/scale));

		

		return biScale;

	}

Using google map on mobile phone

korakot (Korakot Chaovavanich) — Tue, 05 Jul 2005 03:55:36 GMT

Download the tile images for testing



from urllib import urlretrieve

turl =  'http://mt.google.com/mt?v=w2.4&x=%s&y=%s&zoom=%s'

tfile = '%s-%s-%s.gif'

z = 12

for x in range(5,10):

  for y in range(10,14):

    urlretrieve(turl % (x,y,z), tfile % (z,y,x))

Then put the images in the phone. Then use the following code
to browse around the images (and zoom in/out)



from appuifw import *

from key_codes import *

from graphics import Image

import e32



app.screen = 'full'

app.body = c= Canvas()



x, y, z = 10*256, 24*256, 11

dirname = u'C:\\system\\data\\gmap\\'  # where I save the tile images



def draw():

    gx, ox = divmod(x, 256)

    gy, oy = divmod(y, 256)

    f = dirname + '%s-%s-%s.gif' % (z,gy,gx)

    c.blit(Image.open(f), target=(-ox,-oy))



    if ox > 80:

        f = dirname + '%s-%s-%s.gif' % (z,gy,gx+1)

        c.blit(Image.open(f), target=(256-ox,-oy))

    if oy > 48:

        f = dirname + '%s-%s-%s.gif' % (z,gy+1,gx)

        c.blit(Image.open(f), target=(-ox,256-oy))

    if ox > 80 and oy > 48:

        f = dirname + '%s-%s-%s.gif' % (z,gy+1,gx+1)

        c.blit(Image.open(f), target=(256-ox,256-oy))



def move(dx,dy):

    global x, y

    x += dx * 50

    y += dy * 50

    draw()



def zoomin():

    global x,y,z

    x = x*2 + 88

    y = y*2 + 104

    z = z-1

    draw()



def zoomout():

    global x,y,z

    x = x/2 - 44

    y = y/2 - 52

    z = z+1

    draw()



c.bind(EKeyRightArrow,lambda:move(1, 0))

c.bind(EKeyLeftArrow,lambda:move(-1, 0))

c.bind(EKeyUpArrow,lambda:move(0, -1))

c.bind(EKeyDownArrow,lambda:move(0, 1))

c.bind(EKeySelect, zoomin)

c.bind(EKeyStar, zoomout)



running = 1

def quit():

    global running

    running = 0

app.exit_key_handler= quit



draw()

while running:

    e32.ao_sleep(0.1)

I put a bit more explanation in Nokia's forum here. (Newer version is available)
http://discussion.forum.nokia.com/forum/showthread.php?s=&postid=153609
Also see the screenshot here
http://flickr.com/photos/korakot/30189624/

New camera module

korakot (Korakot Chaovavanich) — Sun, 19 Jun 2005 21:56:26 GMT

A few days ago, I posted an example of how to take
a photo with py_s60 1.1.0. But now, a new and better
version (1.1.3) is released. The camera module has
improved significantly.

Now it can
- use different sizes (640x480 and 160x120 in my case)
- use zoom (0 or 1 in my case)
- take photos at 12, 16 or 24-bit color ('RGB12', 'RGB16', 'RGB')
- using flash ('none', 'auto', 'forced', 'fill_in', 'red_eye_reduce')
- set white-balance and exposure (I use 'auto' for both,
but sometimes I may use 'night' exposure)
- return an image object which can save in 'jpg' or 'png' format

You can see that these have good default values

 # copy from camera.py

def take_photo(

  mode='RGB16',

  size=(640, 480),

  zoom=0,

  flash='none',

  exposure='auto',

  white_balance='auto'):

So the simplest example is



import camera

im = camera.take_photo()  # use all default values

im.save(u'C:\\test.jpg')

You can see what you can set on your phone



from camera import *

print image_modes()

print image_sizes()

print max_zoom()

print flash_modes()

print exposure_modes()

print white_balance_modes()