Image Loading Recommendations
lazarus / 39-Graphics

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sfeinst · 2011-11-16 20:01

I have about 50 images to load into my application.  The images on
disk take about 250kb.  Only a couple of images are ever shown at one
time, but over the course of running the app all 50 will display.  The
speed of display of the image during my tests does not seem to matter
if the image is preloaded or not.

I've come up with the following options and am wondering which one (or
if there is another though, that one) makes the most sense.

1) Use a TImageList and add the images at design time.  This will be
the quickest when switching images - though as mentioned above, not
enough to matter.  All  images will be included in the executable
which increases executable size and RAM usage, but removes the need
for me to deploy the images with the application and write code to
figure out where they are located and load them.

2) Use a TImagelist but load the list at form create.  This will have
the same speed (after startup) as #1 and the same RAM usage, but the
executable will be smaller.  Though I will then need a way to find the
deployed images and I will also have to have the user deploy the
images.

3) Use TImage where needed and at runtime load the actual image when
requested.  This will keep memory usage down and executable size down,
but will require deploying the images and writing code to find the
images.  Technically slower as well, though as mentioned, speed has
not been an issue.

In the above, when I mention finding images, I mean determine best way
to tell the application where the images are stored (properties file,
base it off executable location or some other technique I can use). 
Not a lot of code or effort, but more than preloading at design time.

Wondering what others think of the options.

Thanks,

Steve

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lainz · 2011-11-16 23:32

If you load from file, you need to ensure that you use UTF8 for paths
with unicode characters.

In Windows you can run the exe with a different working folder, so you
must ensure that the working folder isn't used in the image path, use
the exe location.

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Swinburne · 2013-04-12 03:12

Hmmmm, compared with your method to load images, i would like to use a
image load program to finish that image loading work. here is a image
loading application  im using now, youc an choose load image from file
or url or your .net graphics.

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User137 · 2013-04-12 05:46

Quote from: sfeinst on November 16, 2011, 09:01:50 pmI have about 50
images to load into my application.  The images on disk take about
250kb.Are they BMP, JPG, PNG or something else, and have you tested
the actual memory use? Those would be very big for JPG's, and
uncompressed could take a decent 200Mb RAM when all are loaded. Just
guessing.

With some simple images like 40x40 size you can easily do options 1 or
2, but with larger i'd go with 3. You can also try loading from
resources or something, to include them in executable. But then the
project will open faster for Lazarus, when you don't have them loaded
in design time always.