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Docu update to match Scaler servlet version 1.6b.
author robcast
date Mon, 03 Feb 2003 17:00:28 +0100
parents 0ff3ede32060
children c7e6d92e7fd5
comparison
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79:63c8186455c1 80:4d0e75042673
4 <TITLE>JBuilder Project ScaleServlet2.jpx</TITLE> 4 <TITLE>JBuilder Project ScaleServlet2.jpx</TITLE>
5 </HEAD> 5 </HEAD>
6 <BODY> 6 <BODY>
7 <H1>Scaler</H1> 7 <H1>Scaler</H1>
8 8
9 <p>A Servlet for scaling images.</p> 9 <p>A Servlet for scaling images. (Version 1.6b)</p>
10 10
11 <p>Scaler takes parameters in the http request format: 11 <h2>Web API</h2>
12 <code>Scaler/request_path/?param1=value1&param2=value2&...</code></p> 12
13 <p>The Scaler servlet takes parameters in the http request format:
14 <code>Scaler/request_path/?param1=value1&param2=value2&...</code>
15 Unknown parameters will be silently ignored.</p>
13 16
14 <p>Recognised parameters: 17 <p>Recognised parameters:
15 <ul> 18 <ul>
16 <li><b>request_path</b> path to file or directory. 19 <li><b>request_path</b> path to file or directory.</li>
17 20
18 <li><b>fn</b> path to file or directory below <code>/docuserver/images</code>. 21 <li><b>fn</b> path to file or directory below <code>/docuserver/images</code>
22 (or other configured image directory).
19 This path will be added to the <code>request_path</code> behind the servlet name. 23 This path will be added to the <code>request_path</code> behind the servlet name.
20 Either parameter can be empty. 24 Either parameter can be empty.</li>
21 25
22 <li><b>pn</b> page number. Index into the (alphabetically sorted) directory 26 <li><b>pn</b> page number. Index into the (alphabetically sorted) directory
23 given by the path. Starts with 1. Ignored if the path points to a file. 27 given by the path. Starts with 1. Ignored if the path points to a file.
24 Default: 1. 28 Default: 1.</li>
25 29
26 <li><b>dw</b> destination image width (pixels). 30 <li><b>dw</b> destination image width (pixels).</li>
27 <li><b>dh</b> destination image height. 31
32 <li><b>dh</b> destination image height (pixels).</li>
28 33
29 <li><b>wx</b> relative x offset of the image area to be sent (0 &lt;= wx &lt;= 1). 34 <li><b>wx</b> relative x offset of the image area to be sent (0 &lt;= wx &lt;= 1).
30 Default: 0. 35 Default: 0.</li>
31 <li><b>wy</b> relative y offset of the image area to be sent. 36
32 Default: 0. 37 <li><b>wy</b> relative y offset of the image area to be sent (0 &lt;= wy &lt;= 1).
33 <li><b>ww</b> relative width of the image area to be sent. 38 Default: 0.</li>
34 Default: 1. 39
35 <li><b>wh</b> relative height of the image area to be sent. 40 <li><b>ww</b> relative width of the image area to be sent (0 &lt;= ww &lt;= 1).
36 Default: 1. 41 Default: 1.</li>
42
43 <li><b>wh</b> relative height of the image area to be sent (0 &lt;= wh &lt;= 1).
44 Default: 1.</li>
37 45
38 <li><b>ws</b> additional scaling factor. The resulting image will have the size 46 <li><b>ws</b> additional scaling factor. The resulting image will have the size
39 <code>[ws*dw,ws*dh]</code>. Default: 1. 47 <code>[ws*dw,ws*dh]</code>. Default: 1.</li>
40 48
41 <li><b>mo</b> flags for the mode of operation separated by "+". 49 <li><b>mo</b> flags for the mode of operation separated by "+".
42 <ul> 50 <ul>
43 <li><b>fit</b>: always scale the image to fit <code>[dw,dh]</code>.<br> 51 <li><b>fit</b>: always scale the image to fit
44 <b>file</b>: send the file as-is (may be very large and all sorts of image types!).<br> 52 <code>[dw,dh]</code>.<br> <b>file</b>: send the file as-is (may
45 If none of these flags is set heuristics is used (send unzoomed GIF as-is). 53 be very large and all sorts of image types!). If configuration
46 54 doesn't allow sending files
55 (<code>sendfile-allowed=false</code>) revert to
56 <code>clip</code>.<br> <b>clip</b>: send the file in its
57 original resolution, cropped to fit <code>[dw,dh]</code>.<br> If
58 none of these flags is set heuristics is used (send unzoomed GIF
59 as-is).</li>
60
47 <li><b>errtxt</b>: send error response as HTML.<br> 61 <li><b>errtxt</b>: send error response as HTML.<br>
48 <b>errimg</b>: response as image (default). 62 <b>errimg</b>: response as image (default).</li>
49 63
50 <li><b>q0</b>-<b>q2</b>: quality of interpolation in scaling 64 <li><b>q0</b>-<b>q2</b>: quality of interpolation in scaling
51 (<code>q0</code>: worst, default). 65 (<code>q0</code>: worst, default).</li>
52 66
53 <li><b>lores</b>: try to use scaled image (default)<br> 67 <li><b>lores</b>: try to use scaled image (default)<br>
54 <b>hires</b>: always use unscaled image.<br> 68 <b>hires</b>: always use unscaled image.<br>
55 If the image is zoomed (ww, wh &lt; 1) the unscaled image is used in any case. 69 If the image is zoomed (ww, wh &lt; 1) the unscaled image is
70 used in any case.</li>
71
72 <li><b>vmir</b>: mirror image vertically.<br>
73 <b>hmir</b>: mirror image horizontally.</li>
56 </ul> 74 </ul>
75 </li>
57 76
77 <li><b>cont</b>: change contrast of the image. Negative value
78 reduces contrast, positive value enhances contrast. Pixel value is
79 multiplied by 2^cont.</li>
80
81 <li><b>brgt</b>: change brightness of image. Negative value reduces
82 brightness, positive value enhances brightness. Pixel value is added
83 brgt.</li>
84
85 <li><b>rot</b>: rotate image. Rotation angle is given in degrees.</li>
86
58 </ul> 87 </ul>
59 The image will be scaled equally in horizontal and vertical direction such that 88 The image will be scaled equally in horizontal and vertical direction such that
60 the resulting image does not exceed the rectangle <code>[ww,wh]</code>. 89 the resulting image does not exceed the rectangle <code>[ww,wh]</code>.
61 </p> 90 </p>
62 91