1. Creating a banner:  

convert -size 650x100 -background  transparent -fill blue \
 -pointsize 64 -gravity center 'label:JP Media & Art Work' logo.png

 This creates a png transparent logo. Parameters can be used to:

 > change the size of the frame.  
 > size of the text.  
 > option '-gravity' helps to put the text at center.

If you want to write a full paragraph with line breaks, do the following:

convert -size 600x180 -background  transparent -fill blue \
 -pointsize 32 -gravity center  caption:'Sometime sky becomes
  so dark\n  I cannot see  stars and lose track \n  when you  
  recognize me \n I know I have not gone too far' poem1.png

note that option '\n' provides the line break. Again this is for transparent. 
If you want  color, do the following:

convert -size 650x100 -background  gray  -fill blue  -pointsize \
   64 -gravity center 'label:JP Media & Art Work'  logo.png

 note that you can control the color of the background as well as that of the text.


2. Handling fonts: 
 
To know what are the fonts avaliable type the following:

convert  -list font

which may give like:

Font: Times-Italic
    family: Times
    style: Italic
    stretch: Normal
    weight: 400
    glyphs: /usr/share/fonts/type1/gsfonts/n021023l.pfb

etc.

Now use the file obtained as the option for '-font'

convert -size 650x100 -background  black   -fill red  -pointsize 64  -font \
  /usr/share/fonts/type1/gsfonts/p052023l.pfb    -gravity center 'label:JP Media & Art Work'  logo.png

3. Positiong a banner on an image :

  convert bg.png  logo.png  -geometry +100+100  -composite tmp1.png

 Note that +100+100 sepecify the location of the banner 'logo.png' and by dynamically
 changing it using some script, snapshots can be created for a movie.


4. Chaging the color or an image :

   convert bg.png   -modulate 60   bg60.png

   smaller the number, darker the image gets.


5. Changing the size of an image 
  convert bg.png   -modulate 60  -resize  1228x1228    bg60.png


6.  Shear an image 
    convert bg.png  -shear 0x30 -resize  1024x1024  -gravity   center bg_shear.png
    convert bg.png  -shear 0x30 -resize  900x600    -rotate -60  -gravity   center bg_shear.png