Automagically adjust gamma level of image.

$cmd = "$input -auto-gamma"; 
exec("convert $cmd auto_gamma.jpg");

Automagically adjust color levels of image.

$cmd = "$input -auto-level"; 
exec("convert $cmd auto_level.jpg");

Automagically orient (rotate) an image created by a digital camera.

$cmd = "$input -auto-orient"; 
exec("convert $cmd auto_orient.jpg");

( Will only work if the camera saves the oriantation to the EXIF data. )

Average a set of images.

$cmd = "$input blue-shift.jpg auto_gamma.jpg -average"; 
exec("convert $cmd average.jpg");

Display the image centered on a backdrop.

$cmd = "$input -background NavajoWhite ". 
"-shear 15x15 -resize 213x" ; 
exec("convert $cmd background.jpg");

( Background sets the canvas colour and will be exposed when using other operators like rotate and shear. You can have a background of none which is transparent but the image must be saved as a gif or png. )

Measure performance.

$cmd = "$input -resize 1000% -bench 3 "; 
exec("convert $cmd big.png 2>&1",  $output); 
print_r($output);

( Repeat the entire command for the given number of iterations; report the user-time and elapsed time.
Modify the benchmark with the -duration to run the benchmark for a fixed number of seconds and -concurrent to run the benchmark in parallel (requires the OpenMP feature).
3 iterations were completed at 0.158932 iterations per second. )

Add bias when convolving an image.

$cmd = "$input -convolve \"-1,0,1,-1,0,1,-1,0,1\" -bias 20% ";  
exec("convert $cmd bias.jpg"); 
 

$cmd = "$input -black-threshold 30%";  
exec("convert $cmd black_threshold.jpg");

( Force to black all pixels below the threshold while leaving all pixels at or above the threshold unchanged. )

Blackpoint compensation for a colour profile.

$cmd = "$input -intent relative -black-point-compensation".
" -profile CMYK_PROFILE ";
exec("convert $cmd black-point-compensation.jpg");

Blend an image into another by the given percent.

$cmd = "-size 213x160 xc:blue miff:- ". 
"| composite $input +swap -blend 70 - "; 
exec("convert $cmd blend.jpg");
  

( This is creating the blue image to blend as well as blending the two images. *** should be able to define the size of the blue image from the size of the image *** )

Set the blue chromaticity primary point.

$cmd = "$input -blue-primary 80,80";   
exec("convert $cmd blue-primary.jpg");
 

Simulate a scene at nighttime in the moonlight. Start with a factor of 1.5

$cmd = "$input -blue-shift 1.5 "; 
exec("convert $cmd blue-shift.jpg");

Reduce image noise and reduce detail levels.

$cmd = "$input -blur 15"; 
exec("convert $cmd blur_simple.jpg");

$cmd = "$input -blur 0x3"; 
exec("convert $cmd blur.jpg");