ASP & Database

Discussions on GFL SDK, the graphic library for reading and writing graphic files

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RomanDA
Posts: 1
Joined: Mon Dec 11, 2006 12:25 pm
Location: NC

ASP & Database

Post by RomanDA » Mon Dec 11, 2006 1:35 pm

I have a database setup for my web site that stores images.

the code I have to use in an IMG tag is:

Set oConn2 = Server.CreateObject("ADODB.Connection")
Set oRS2 = Server.CreateObject("ADODB.Recordset")
oConn2.Open "DRIVER={Microsoft Access Driver (*.mdb)};DBQ=" & Server.MapPath("/database/database.mdb")
strSQL="SELECT * FROM " & Request("db") & " where id = " & Request("id")
oRS2.Open strSQL, oConn2, 3, 1
Response.ContentType = "application/octet-stream"
Response.AddHeader "Content-Disposition", "attachment;filename=" & Trim(oRS2(FileName))
Response.AddHeader "Content-Length", oRS2(FileSize)
Response.BinaryWrite oRS2(PicName)
oRS2.Close
oConn2.Close
Set oRS2 = Nothing
Set oConn2 = Nothing

The issue is, i would like to use GflAx to resize these images when they are shown on the web page.

I have looked at using the following:

pn = oRS2(PicName)

img.enablelzw= True
img.ReceiveBinary PN

But i get an error:

GflAx.GflAx.1 error '80004005'
Bad parameters : 16396


PLEASE help, I do not want to have to store the images on the server in a directory, I like having them as part of the database.

b.e.wilson
Posts: 26
Joined: Wed Mar 09, 2005 7:44 pm

Post by b.e.wilson » Fri Dec 22, 2006 5:13 pm

Well, I hope by now you've figured out why no one has yet responded. Putting images in a database is a might poor way of doing things, and if you haven't paid attention to the advice I know you've read already, why would we think you'll listen to what we have to say.

Anyway, here's a nice bit of annotated ASP code from which you may see the way out of your problem:

Code: Select all

<%
'image.asp
'Code by Bruce Wilson, UVSC
'This code is called in a <img> tag as follows:
'<img src="image.asp?f=filename&c=txt&x=n&y=n&w=n&h=n&dh=n&dw=n"> where n are integers

set GflAx = Server.CreateObject("GflAx.GflAx")
GflAx.LoadBitmap Request.QueryString("f") 'f=path to the file, came from the database
c = request.querystring("c") 'name of copyright holder
x = Request.QueryString("x") 
y = Request.QueryString("y") 
'x and y define the top left corner of the section of the image to be viewed. 
w = clng(Request.QueryString("w")) 'the width of the crop. A long variable is needed for the if-then
h = clng(Request.QueryString("h")) 'the height of the crop
dh = Request.QueryString("dh") 'DisplayHeight, the height of the image to be delivered
dw = Request.QueryString("dw") 'displayWidth, the width of the image to be delivered
fw = GflAx.width 'full image width
fh = GflAx.height 'full image height
m = fw/w 'magnification factor
s=30 'sharpening factor, scales for different levels of magnification; more sharpening is used 
if m>150 then s=35
if m>300 then s=50
'don't crop if the entire image is requested:
if (w<fw) OR (h<fh) then GflAx.Crop x, y, w, h
GflAx.Resize dw, dh
GflAx.Sharpen s
if c<>"" then 
  With GflAx
    .FontSize = 24
    .FontName = "Georgia"
    .FontBold = True
    .FontItalic = True
    .TextOut c, 15, dh-24, RGB(255,255,255)' white shadow
    .TextOut c, 14, dh-26, RGB(0, 64, 0) 'dark green text
  end With
End If
'Gflax.EnableLZW = True 'only needed for GIF images
GflAx.SaveFormat = 1 '1=JPEG, 2=GIF, 3=PNG, 4=BMP, 5=TIFF
GflAx.SaveJPEGProgressive = TRUE
GflAx.SaveJPEGQuality= 85 'this can be raised to 100 for better image quality at the expense of bandwidth
Response.ContentType = "image/jpeg"
Response.BinaryWrite GflAx.SendBinary
set GflAx = nothing
%>

b.e.wilson
Posts: 26
Joined: Wed Mar 09, 2005 7:44 pm

Post by b.e.wilson » Fri Dec 22, 2006 5:16 pm


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MaierMan
Posts: 78
Joined: Wed Aug 04, 2004 8:32 pm
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Post by MaierMan » Thu Feb 01, 2007 7:25 pm

b.e.wilson wrote:Well, I hope by now you've figured out why no one has yet responded. Putting images in a database is a might poor way of doing things, and if you haven't paid attention to the advice I know you've read already, why would we think you'll listen to what we have to say.
Generating images on-the-fly over and over again is bad too.
I agree that serving images from a database is bad because of
  • overhead (ASP, DB queries),
  • bypassing OS optimizations where available (e.g. sendfile, disk caches, server-internal optimizations)
  • and usually the incorrect/imcomplete implementation (like yours):
    • missing cache headers/handling of those. (performed by the server when it comes to static files). Think "304 - Not modified" :p
    • missing Filename, Size and so on.
But it is still better to cache images in a DB than regenerating on each hit.

You both, what do you think your server will do when there are several hundred hits/sec?
It will choke or even get completely unresponsive.

Furthermore, RomanDA, why is there a manual?
GetBlob/SetBlob? How about those?

b.e.wilson
Posts: 26
Joined: Wed Mar 09, 2005 7:44 pm

Post by b.e.wilson » Fri Feb 02, 2007 4:48 pm

Well, my servere will choke. Take a look at the paqe I posted and see if you want to pre-make and cache all the versions that might be called for.

We push imaging to different processes right now anticipating the move to different servers.

And take another look at the page I posted and say when we might anticipate 100 hits/sec.

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