JES

CS155 Computer Graphics

The purpose of this tutorial is to introduce you JES, a python environment for image processing.

Download the following image to your desktop:
Open JES
At the command line enter:
```
 
file=pickAFile()
```
Navigate to the downloaded file and open.
At the command line enter:
```
 
pic=makePicture(file) 
show(pic) 
```
The image should display in a separate window.
At the command line enter:
```
 
print pic
```
Info on the picture will be displayed including its height and width.
Click on MediaTools in the JES toolbar then select Picture Tool. Say OK to "pic." A new window should open.
Click on Harry. The RGB values for the selected pixel will be shown. Notice that JES uses integers 0-255 to represent color values.
Copy the following program into the editor.
```
def shift(pic):
	for p in getPixels(pic):
	r=getBlue(p)
	g=getRed(p)
	b=getGreen(p)
	setColor(p,makeColor(r,g,b))
return
```
Save the program then load and run it with the command:
```
 
shift(pic) 
```
(If you get in error it may be that the indentation was reformatted during the copy. Redo the indentation.)

At the command prompt enter:

 
repaint(pic)


At the command prompt enter writePictureTo(pic,pickAFile())
Navigate to the desktop and save the file as "HarryNew.bmp".

For more information or to download JES go to jes website. Last updated Aug. 09