Contents of /trunk/libjpeg/patches/libjpeg-6b-crop-man.patch
Parent Directory | Revision Log
Revision 144 -
(show annotations)
(download)
Tue May 8 20:06:05 2007 UTC (17 years, 4 months ago) by niro
File size: 2056 byte(s)
Tue May 8 20:06:05 2007 UTC (17 years, 4 months ago) by niro
File size: 2056 byte(s)
-import
1 | # DP: Manpage update for jpegtran -crop |
2 | |
3 | diff -urNad /home/bill/debian/libjpeg/libjpeg6b-6b/jpegtran.1 libjpeg6b-6b/jpegtran.1 |
4 | --- /home/bill/debian/libjpeg/libjpeg6b-6b/jpegtran.1 2003-09-22 18:46:08.000000000 +0200 |
5 | +++ libjpeg6b-6b/jpegtran.1 2003-09-22 18:49:06.000000000 +0200 |
6 | @@ -131,6 +131,40 @@ |
7 | .B \-rot 180 -trim |
8 | trims both edges. |
9 | .PP |
10 | +If you are only interested by perfect transformation, add the |
11 | +.B \-perfect |
12 | +switch: |
13 | +.TP |
14 | +.B \-perfect |
15 | +Fails with an error if the transformation is not perfect. For example |
16 | +you may want to do |
17 | +.TP |
18 | +.B (jpegtran \-rot 90 -perfect foo.jpg || djpeg foo.jpg| pnmflip \-r90 | cjpeg) |
19 | +to do a perfect rotation if available or an approximated one if |
20 | +not. |
21 | +.PP |
22 | +We also offer a lossless-crop option, which discards data outside a given |
23 | +image region but losslessly preserves what is inside. Like the rotate and |
24 | +flip transforms, lossless crop is restricted by the JPEG format: the upper |
25 | +left corner of the selected region must fall on an iMCU boundary. If this |
26 | +does not hold for the given crop parameters, we silently move the upper left |
27 | +corner up and/or left to make it so, simultaneously increasing the region |
28 | +dimensions to keep the lower right crop corner unchanged. (Thus, the |
29 | +output image covers at least the requested region, but may cover more.) |
30 | + |
31 | +Note: |
32 | +.B \-perfect |
33 | +and |
34 | +.B lossless-crop |
35 | +are enhancements from http://sylvana.net/jpegcrop/ that may not be available on |
36 | +non-Debian systems. |
37 | + |
38 | +The image can be losslessly cropped by giving the switch: |
39 | +.TP |
40 | +.B \-crop WxH+X+Y |
41 | +Crop to a rectangular subarea of width W, height H starting at point X,Y. |
42 | +.PP |
43 | +.PP |
44 | Another not-strictly-lossless transformation switch is: |
45 | .TP |
46 | .B \-grayscale |
47 | @@ -231,7 +265,9 @@ |
48 | .PP |
49 | The transform options can't transform odd-size images perfectly. Use |
50 | .B \-trim |
51 | -if you don't like the results without it. |
52 | +or |
53 | +.B \-perfect |
54 | +if you don't like the results. |
55 | .PP |
56 | The entire image is read into memory and then written out again, even in |
57 | cases where this isn't really necessary. Expect swapping on large images, |