Annotation of /trunk/libjpeg/patches/libjpeg-6b-crop-man.patch
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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 | niro | 144 | # 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, |