The other important piece within this dialog to consider
is the Resolution.
Dealing with resolution could be a whole tutorial in itself.
The key here is to understand that images are used for
different purposes and each purpose may require a different
resolution. This is actually a good thing since each purpose
is served best by different resolutions.
For example, for working on the web, or for
sending an image via e-mail, where the computer monitor
is the final "use" for the image, the resolution recommended
is 72 dpi or pixels per inch.
However, if you want to print
an image, you would want a higher resolution image and
what that resolution should be depends on your printer.
Many printers today can handle 600 dpi output or higher.
However, to make things really confusing, this doesn't
mean you should necessarily have an image that can match
the maximum resolution of the printer's highest quality
output - you need to look at each printer manual and experiment.
Often lower resolution give better results (Well, they
do for me!)
If your final output is for printing by a commercial printer
- say for a color newsletter, check with your printer to
determine what resolution they require for their processes.
It gets even more complicated since printers use lines
per inch when creating the color print screens to produce
the pictures so check with the printer.
Improper resolution for the purpose is why images on your
computer screen don't print as nice as they look on the
monitor. The screen resolution is 72 dpi, the printer often
is 600 dpi or better. Look at the resizing example above,
the same thing happens when you try to print an image from
the web or e-mail, the printer and or computer must interpolate
the data to the size of the image and you'll often get
poor print quality - the same thing's happening as in the
resizing up example above.
The key point here - images have different intended uses:
web, home printing, commercial publishing. Each of which
may require different resolutions to get you the best quality
for each task. Save/archive the original image
and resize appropriately for each task.
Now, let's look at image formats - another
possible tutorial in itself, but I'm going to deal briefly
with just four here: TIFF, PSD, JPG and GIF. What are the
differences and what is each used for?
TIFF stands for Tagged Information Formal
File. It's the highest quality 'flat' image and commonly
the format requested by commercial printers. TIFF is a
'lossless' image format; there is no compression going
on when the image is saved, thus retaining the most information
and highest quality. TIFF images are also usually large.
PSD is Photoshop's native file format.
When we begin looking at layers below and you want to save
an image and make changes to the layers later, you MUST
save a version of the file in the PSD format. None of the
other formats mentioned here supports layers. Even if the
eventual outputted format may be a TIFF, GIF or JPG file,
saving the PSD is almost always a good idea, especially
if you think you may have to make changes to the image
at any point in the future. PSD files, because they support
layers, can be very, very large however. The PSD format
supports alpha channels - more on these later.
JPEG or JPG - Joint
Photographic Experts Group - (Pronounced "Jay Peg").
This is the format of choice for photo images
which must be made into very small files; for example,
for web sites or for E-Mail. JPG is also used in digital
cameras, but TIFF or RAW formats may be options too, in
order to avoid the JPG Format.
Why avoid it?
JPG files can be amazingly small, often compressed to
1/10 of the size of the original raw image data. However,
this compression comes with a very high price. JPG uses "lossy" compression
(lossy here means "with loss of image quality and
Lossy means that some image data is lost when the image
data is compressed and saved, and this data can never be
recovered. This is another reason for always retaining
a PSD file image - the compression and loss of data occurs
during the conversion to the JPG format.
Photoshop offers a Save For Web... option in the File
menu. The key here is to work in the .psd file format up
until the image is completely scaled, adjusted, labeled,
and/or what ever else needs to be done. Save the image
in psd format and then as the last step do a Save For Web...
while ALWAYS retaining the original .psd. If you have to
go back later to modify a .jpg file and do a Save for Web...
again, further data and quality will be lost.
Photoshop and most other graphics program let
you set the amount of compression during the saving process;
smaller file sizes means more data and quality loss but
load faster on the web, especially over modems.
GIF - Graphics Interchange Format.
This format includes some features which makes it
a unique and a valuable format for the Internet. These
features include file compression, transparency, interlacing
and storage of multiple images within a single file (which
allows for a primitive form of animation). This is the
only web file format here that supports a "transparent" color
in the image (web browser can't display .psd files). GIF
files are also responsible for the annoying animated
pop-ups and dancing/moving images on web sites. Their biggest
"problems" are they only support a maximum of 256 colors
in any one image and they are inappropriate for printing
purposes of any kind. Their advantages are they can be
very small when needed, can be animated and have parts
that can be transparent.
Transparency leads to our discussion and demonstration
of Photoshop Layers.
When you first open
an image in Photoshop there is only one layer - the background
layer. By default the background layer is usually opaque
and set to the background color - usually white. We'll
look at how to get around the opaque issue below and just
so you are aware, there is an option in New File to create
the new image with a transparent background too.
a number of way to add additional layers to an image and
each layer can have parts that are opaque, completely transparent
or something in between.
An easy way to visualize Photoshop's layers is to imagine
a photo with sheets of glass stacked on top of that background
image. Each piece of glass represents a layer. If you
place a leaf on each piece of glass, each layer can be
moved independently with part of the layer still being
An alpha channel is the part of an image that describes
transparency. We learned in earlier tutorials
here that each pixel is made up of RGB or HSB values, in
fact, each image has a Red, Blue and Green channel. The Alpha
Channel adds one more item of data, a level of transparency
for each pixel in the layers.
Photoshop has a layers palette - it appears by default
on the right when you open a new image.
To demonstrate how layers work and some of their features,
I'm going to go step by step into creating the image below:
This image is built on
a white background initially.
It's got 4 layers altogether
and uses the same image of H. 'Siloam Double Classic'
as I used above for the background and for the flower.
I started by creating a new image and making it
450x450 pixels. I chose white for the default background
To create the two colored frames I first used the
Rectangular Selection Tool. I held the Shift Key
down while I dragged the Tool to form a square (holding
the Shift key down restrains the tool to a perfect
square rather than a rectangle.) I chose a dark brown
foreground color. I then went to the Edit Menu and
selected Stroke... and chose 25 pixels set to "Inside"
in the Dialog that appears. This created the darker
frame. I then chose the Magic Wand selection tool.
clicked inside the brown frame to select the white
area inside the frame. I selected a neutral gray
color and using the Stroke dialog again I applied
an 18 pixel inside stroke. I then once again used
the wand selection tool to click inside the new frame
to select the white area inside both frames.
Now, I want to make this selection transparent. This takes
two steps - first, I need to make the background layer into
a layer that can support alpha channel transparency.
Here's the layer palette at this point:
The 'eye ball' icon above indicates
that this layer is currently 'visible'. You can click
on the eye to have the layer become 'invisible' and
click again to have it reappear. This is handy for
trying various things to see which looks better.
You can see a couple of
things here we should note. First, there's just the
one layer still and it's locked. All the options above
are grayed out because the layer doesn't support alpha
channels yet. Changing this layer to support alpha
channels is really simple, just double click the word
Background in this palette and a dialog will appear.
Click OK and the background layer will be converted
to Layer 0 which does support alpha channel transparency.
Now, if we still have the inner white square inside the
frames selected (if not, select it again) we can make this
transparent. To do this, go back to the Edit menu and select
Clear. This inner square should now have a gray and white
checkerboard pattern. This is Photoshop's way of telling
you that portion of the image is now transparent - when
there's no opaque background layer the 'bottom' is shown
by this checkerboard - it doesn't show in your final images,
it's just a visual clue for you.
To prove this is now transparent, I open my
original large image of H. 'Siloam Double Classic' and
select an oversized portion of the background area (you
can have more than one image open at the same time and
switch between them at the bottom of the Window menu.)
I got a nice out of focus mix of green and black. My selection
was overly large because I don't want to worry if it's
big enough. With this area selected I chose Copy from the
Edit menu. I now switch back to my frames image and chose
Paste from the Edit menu. Each time I choose Paste, Photoshop
will create a new layer for the pasted item and put it
on this new layer.
However, when I do this I get the new layer
placed above the frames. Thankfully, Photoshop's programmers
have made rearranging the layers easy.
To rearrange the layer order, simply
click on Layer One in the palette and drag in down
below Layer 0 in the palette area and release the mouse
button. It should now appear as the palette at the
right and you should be able to see the green-black
background layer beneath and through the opening
in the frame on the image you are working on.
I now want to select the flower in the Siloam image.
To do this I can use a number of tools, go back to Tutorial
3 to see how to use the Magnetic Lasso Tool. Since I just
got Photoshop CS3 I used the new Quick Select Tool. This
tool alone was worth the upgrade, as I was able to simply
paint around the flower area and 20 seconds later the whole
flower was selected - it's amazing! You can also try using
the wand tool and holding down the shift key keep clicking
on parts of the flower until it's all selected - you'll
probably have to do some cleanup with the 'normal' lasso
tool like described in Tutorial 3 as well.
Once you have the flower selected, choose Copy from the
Edit menu and then select New under the File menu. Photoshop
should open a new file dialog that's set to accept the
size image that's last been copied and is on the clipboard.
Click OK and then Paste from the Edit menu. I did this
as a new graphic because I need to resize the flower before
I paste it into my image - the image at this stage was
roughly 1600 pixels square at 180 dpi. I used the Image
Size dialog to change the resolution to 72 dpi and the
width to 300. I then selected the layer with the flower
in the Layers palette by clicking on it, chose Select All
in the Edit menu and chose Copy from the Edit menu again.
I now switched back to my project image and selected Layer
0 again. I want to Paste the flower above Layer 0 and Photoshop
creates the new layer above the currently selected layer.
I now chose Paste from the Edit menu and the flower appears
- looking like this.
This got the flower in
place, but it appears flat. One nice thing about
layers is that different effects can be applied to
a layer, so in this case I'm going to select the
layer with the flower and then go up to the Layer
Menu - Pick Layer Style and within that menu choose
Drop Shadow. I opted to change the Distance to 12
and the Size to 10. This makes the flower appear
to float above the frame and background.
When you have multiple layers you can move the items
on each layer around independently using the Move
selection tool, it's the one that looks like this.
I chose that tool and dragged the flower image layer
up and to the left - notice the drop shadow, which
has various degrees of transparency, moves with the
flower - the rest of the image stays put.
I now want to label this image.
I first want to
select the color so I used the eye dropper and picked
a pink from within the flower image. I selected the
Text Tool from the main tool palette, the one that
looks like the letter T. I clicked on the area and
typed the name, choose a font and size and in this
case choose to right justify the text. I then also
moved it to just where I wanted it and applied a
drop shadow to the text layer.
This leaves me with the four layers
- dark black green background, frames with white
outline, flower with large drop shadow effect, text
with default drop shadow effect, the palette looks
like this now.
A couple more things about the layer palette - at
the bottom are a number of icons, the two most often
used by me are the trash can - select a layer and
click the trash can to delete that layer and the
one next to the trash, the New Layer icon -
click on that to create a new empty layer. If you
select a couple of layers at the same time (try holding
the Control Key, PCs and Command Key - Macs) and
select more than one layer at once. Now you can click
the chain icon to link these layers together - now
if you move one, those linked together move as a
group. You can lock a layer once you have it 'perfect'
by clicking the lock icon. Each layer can also be
adjusted for opacity - I often create label text
and set it to 50% opacity to make it less 'glaring'
and distracting from the flower.
Many of the layer effects have the Preview option
as well so you can see how they affect the layer
before you apply them - note too that the layer effects
have the eye icon, so you can hide an effect without
hiding the whole layer.
Next to last in the process, you should Save this as a
Photoshop PSD file - this will retain the layers, so if,
for instance, you misspelled the name of the flower, you
could go back and edit the text layer and not have to start
the image over from scratch to fix that.
The last step is to 'flatten' the image and save it in
another format. For saving as a JPG file you can use the
Save for Web... dialog - this will bring up a dialog panel
( full screen so too big to show here). If it's not by
default shown, click the 4-Up tab and you will see four
versions of the image, all with different compression levels
shown - you can make adjustments to the compression level
slider - try to make the image as small as possible while
retaining the highest image quality. A quality setting
of 65% yields good results for me on most images. A JPG
file doesn't support layers so the saved JPG file will
already be flattened. However, say you want to Save As...
in the TIFF format. You should manually flatten the image
before doing that. Go to the Layer Menu and choose Flatten
Image and then Save As... and choose the TIFF format in
the pull down menu for file formats.
For those of you interested, here's a link HERE to
my .psd file for this project, with the layers still intact.
PC users, right click on the link and choose Save to Disk,
Mac users without a two button mouse, Control-Click on
the link to download the file as well. Please note that
as a .psd file with four layers, this will be a 1.8 meg
download, the final jpg image below is just 36K.
Once again, here's the final image.
Now, Veronica Glover stated. "I would appreciate a tutorial
on how to cut out a daylily with a transparent background.
I worked 3 hours trying to do this but when I transfer
the image the background is white."
Veronica, part of the answer maybe that you pasted the
cut flower onto a white background - new files in Photoshop
often default to having a white background layer. Or, the
answer may be you chose the wrong image format for final
output. Had you chosen GIF you may be been able to retain
the transparency, but you would have been limited to just
256 total colors; one of which is assigned to be transparent.
There's also a newer file format called PNG which supports
a transparent layer, but not all web browsers support the
.png format. Hopefully, you can look at the process above
and figure out what went wrong in your attempt.
One easy way to 'force' a transparent background is to
paste the flower onto a white background, then double click
the background layer and answer OK to convert it to a standard
layer. Then select this white layer by clicking on it
in the layers palette and then click the Trash Can icon
at the bottom of the layers palette to delete the background
layer. I used this technique to create the flower image
below, and saved this as a GIF - since there's a transparent
background in the image, Photoshop assigned the background
"color" to be transparent.
As a final example, I created a bee striped background
and saved it as a GIF file too - no transparency. With
only two colors in this file, it's less than 2K in size,
despite it's being 770 pixels wide by 409 pixels high.
With limited colors, GIF files are great. I created an
HTML table below and set the bee stripe image as the background
for the table and then put the GIF file I created from
the same H. 'Siloam Double Classic' image and placed it
in the table too "on top" - you can see how the
background of the image is transparent (and I went with
a loud and gaudy background to make that point!) But also
notice there's a little white around the edges in places
and especially in the throat area, if you look closely,
you can see there's only a limited number of colors there
- Photoshop does do an incredible job of selecting the
best 256 colors to use for this process.
The GIF image of the flower however is 53k whereas the
JPG file above with far more colors is only 36K.