Re: eRPG; where are my images

My experience is that nothing is lost and universality is won when one 
stays to an 8.3 naming convention.  Everyone's software understands 
myfile.txt and mypic01.jpg.  Longer names are nice but mixing cases, 
inserting blanks, and hidden extensions just cause unneeded troubles, 
especially when the Internet is still so new.  As the world begins moving 
to the new Internet Appliances and hand-helds we are going to see more and 
more browser incompatibility imho, so staying with the lowest common 
denominator makes sense unless there is a compelling argument to the 
contrary.

_______________________
Booth Martin
Booth@MartinVT.com
http://www.MartinVT.com
_______________________




Rob Dixon <rob.dixon@erros.co.uk>
Sent by: owner-midrange-l@midrange.com
06/24/2000 05:55 AM
Please respond to MIDRANGE-L

 
        To:     MIDRANGE-L@midrange.com
        cc: 
        Subject:        Re: eRPG; where are my images

John

I found that whilst Netscape would not access image with blanks in their 
name,
Internet Explorer would.

i.e. if any of your users use Netscape, you should use

my_image.jpg

and NOT

my image.jpg

This applies from Netscape 3.0 to 4.72 .

In addition, even the file extension must be in the correct case.

I also always send the browser the full URL with IP address for my own 
system but
with domain name for other systems.  Hans gave the example -

<img src="http://www.abc.to/dirname/images/image.gif">

(Has Toronto moved to Tonga?)

I store only

dirname/images/image.gif

for images on my own system and use code to generate the remainder 
including my
own system IP address.  This has the advantage of less typing and so less 
room
for error and if you change system, you do not need to retype all your 
image
URL's.  Using the IP address means that the address does not have to be 
looked up
and this should improve performance.

For systems over which I have no control, I store

www.abc.to/dirname/images/image.gif

and generate the rest.

I find jpg gives better quality images than gif.

One advantage that Netscape has over IE (apart from the fact that it is 
not an MS
product) is that if you send a larger image than you wish to be displayed
initially and generate appropriate "HEIGHT" and "WIDTH" parameters so that 
it is
displayed initially in the smaller size, users can right click on an image 
and
select "view image" in which case it will be displayed in the maximum 
size.  I am
not aware that you can do this in IE unless you send a request back to the 
server
and the server sends a larger image file.

I generally send ten images at a time, together with any data or text 
retrieved
from my database, and display these in two rows of five images each with 
their
own data.  Anyone requiring a more detailed image can just right click on 
it. If
I know that only one image will be sent, then I send it in the larger 
size.

Sending all images in larger size means that more traffic is sent down 
your
network when users only look at the small size but less when they look at 
two
sizes if you use a method that depends on sending a second file for the 
same
image.  I find that using jpg files with minimal quality and so maximum
compression means that a black and white image say 772 x 600 pixels is 
about 37k
which is not too bad on a local network and works OK over the Internet. 
Colour
images tend to be larger so I reduce the maximum size when creating the 
jpg file.
Given that the quality of the very best screens is relatively poor, the
difference in image quality on a screen between pictures with zero 
compression
and those with maximum is not so great.  Maximum compression allows people 
to
look at quite large images for identification purposes yet those images 
are not
of adequate quality for them to steal and publish in printed form (unless 
on a
postage stamp).  The maximum size that you transmit will obviously depend 
on the
use to which the images are put.  The amount of compression that you can 
get away
with will depend on whether the image is tonal - e.g. a photograph or 
painting -
or is made up of lines - an engineering or architect's drawing or an 
etching.

I hope this helps.

BTW, can anyone tell me how to get image details such as image size from, 
say, a
jpg file directly into an AS/400 file.  At present these have to be typed 
in.

Rob Dixon

rob.dixon.vcf

STG42502