Improving Page Download Time With Image Compression
by Nannette Thacker
It would be rare for a developer to work on a website without
having to do something with the images. And if you're a one-person
team, you'll likely have to do the image compression yourself.
To show the importance of image optimization, I took a page
with 64 HTML images and ran it through a page load test. I then
optimized the images and ran it through the test again. For my testing, I used the free
Web Page Analyzer
Image Size in Bytes
56K Download In Seconds
ISDN 128K Download In Seconds
T1 Download In Seconds
Remember that the majority of internet users do not have access to a high-speed
cable service, so keeping your site's download size low is essential.
Below is the technique I used to optimize the images.
Batch Image Optimization Using Adobe Photoshop
With Adobe Photoshop, you can batch compress your images for
the web. To do this, we must first open an image, in Photoshop,
and record as we save the file with compression. Then we can
use the Automate / Batch process to automatically process all
of our files with the same amount of compression.
Open Photoshop. Then select to open one of your files that you
desire to have compressed:
Then open the Actions Pane by selecting Window > Actions:
Select the "Create New Action" icon to record a new action:
Name your New Action. I've named mine "CompressWeb" as shown
After naming your Action, select the "Begin Recording" icon.
Since your image is already opened, simply select the File /
Save for Web menu item to bring up the dialog box to save the
image. In the below screenshot, you'll see we've saved the file
type as "JPG" and the quality at "50." Then select the Save
button. I saved my compressed image into a new directory I had
previously created called "Resized."
In the Actions pane, select the "Stop playing/recording" icon.
Now we are ready to begin batch compression of our directory.
From the File menu, select the Automate > Batch... menu items.
The Batch dialog box will appear. Select your Action as "CompressWeb."
Use the Source drop down to select on which files to perform
the Action. I selected "Folder." Select the "Choose..." button.
Optionally, you may also select to "Include All Subfolders."
The "Browse for Folder" dialog box will open, allowing you to
"Choose a batch folder..." for the action. Select "OK."
Our first test file used for setup is found in the target location,
so a "Replace Files" dialog box will appear. You can leave it
selected (it will simply perform the compression on the original
file again), or deselect the box and select "Replace."
Upon selecting "Replace," Photoshop will automatically open
all of the files in the directory and perform the compression
on each, and save them.
When you are done, you can view the file sizes for the newly
compressed directory versus your original directory and see
the the compressions were performed successfully.
When done, select the File > Close All to close all the files.
Photoshop wil ask you if you wish to "Save changes... before
closing?" Select "No" for each one since you have already saved
the file with the desired compression.
The above steps work successfully with "Destination" = "None"
if you create your destination folder in advance, and save your
original sample file to that destination folder during recording.
However, the Batch screen provides other options to select "Folder"
for your "Destination" and "Choose" the folder. This also allows
Photoshop to Batch rename your files during the Action.
May your dreams be in ASP.net!