functions in jpeg.i - j

    image = jpeg_read(filename)  
 or image = jpeg_read(filename, comments)  
 or shape = jpeg_read(filename, comments, [0,0,0,0])  
 or image = jpeg_read(filename, comments, subset)  


  
Read jpeg file FILENAME.  The returned IMAGE is 3-by-width-by-height  
for rgb images (the usual case) or just width-by-height for grayscale  
images.  Note that the scanline order is top-to-bottom.  
If COMMENTS is present, it must be a simple variable reference.  
That variable will be set to either nil or a string array containing  
all the descriptive comments in the file.  
  
In the third form, the return value is [nchan,width,height] instead  
of the image, where nchan=1 or nchan=3.  
In the fourth form, SUBSET is [i0,i1,j0,j1] and the returned image is  
the subset full_image(..,i0:i1,j0:j1) of the full image.  (This is  
inefficient, but, for example, some Mars Rover pictures released by  
NASA are inconveniently large.)  
  
   Builtin function, documented at i0/jpeg.i   line 9  

    jpeg_write, filename, image  
 or jpeg_write, filename, image, comments, quality  


  
Write jpeg file FILENAME containing IMAGE at the specified QUALITY.  
The default QUALITY is 75; the range is from 0 to 100.  The IMAGE  
can be either 3-by-width-by-height for rgb or width-by-height for  
grayscale.  Note that scanline order is top-to-bottom.  
If COMMENTS is non-nil, it is a string or an array of strings that  
will be written as descriptive comments in the jpeg file.  
  
   Builtin function, documented at i0/jpeg.i   line 32