[Image-SIG] PIL Jpeg resizing in windows

Jim Tittsler jwt at onjapan.net
Sun Aug 5 11:44:15 CEST 2007

On Jul 30, 2007, at 07:34, Neil Johnson wrote:

> I am new to using PIL and trying to find out how to resize JPEG  
> images.  I try to resize, and I always get a "pixel access" error  
> using the thumbnail, resize, or load functions.  Do I need to build  
> the PIL from source in order to have JPEG resizing capability?


How large is your source image?

> infile = "image1.JPG"
> PicMaxHeight = 128

Not related to your problem... but you probably will want to do  
floating point division.

> im = Image.open(infile)
> im.load()
> file, ext = os.path.splitext(infile)
> ActualSize = im.size
> heightScale = ActualSize[1]/PicMaxHeight
> scaleFactor = heightScale
> newSize = ActualSize[0]/scaleFactor, ActualSize[1]/scaleFactor
> ## Now let's try resizing...cross your fingers!
> im.resize(newSize)

Note that the resize() method returns a resized *copy* of the image.   
It does not modify the original.

it = im.resize(newSize)

Jim Tittsler     http://www.OnJapan.net/      GPG: 0x01159DB6
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