libjpeg API: Partial scanline decompression
This, in combination with the existing jpeg_skip_scanlines() function,
provides the ability to crop the image both horizontally and vertically
while decompressing (certain restrictions apply-- see libjpeg.txt.)
This also cleans up the documentation of the line skipping feature and
removes the "strip decompression" feature from djpeg, since the new
cropping feature is a superset of it.
Refer to #34 for discussion.
Closes #34
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 91c8ac6..7f19043 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -367,9 +367,9 @@
set(MD5_PPM_420M_ISLOW_1_4 35fd59d866e44659edfa3c18db2a3edb)
set(MD5_PPM_420M_ISLOW_1_8 ccaed48ac0aedefda5d4abe4013f4ad7)
set(MD5_PPM_420_ISLOW_SKIP15_31 86664cd9dc956536409e44e244d20a97)
- set(MD5_PPM_420_ISLOW_PROG_STRIP71_132 a5c3706bb2e59bd01786b1181f67f97c)
+ set(MD5_PPM_420_ISLOW_PROG_CROP62x62_71_71 452a21656115a163029cfba5c04fa76a)
set(MD5_PPM_444_ISLOW_SKIP1_6 ef63901f71ef7a75cd78253fc0914f84)
- set(MD5_PPM_444_ISLOW_PROG_STRIP13_110 6d228f8d05381d8639f3d078b91b2ee0)
+ set(MD5_PPM_444_ISLOW_PROG_CROP98x98_13_13 15b173fb5872d9575572fbcc1b05956f)
set(MD5_JPEG_CROP cdb35ff4b4519392690ea040c56ea99c)
else()
set(TESTORIG testorig.jpg)
@@ -421,11 +421,11 @@
set(MD5_BMP_420M_ISLOW_565D d1be3a3339166255e76fa50a0d70d73e)
set(MD5_PPM_420_ISLOW_SKIP15_31 c4c65c1e43d7275cd50328a61e6534f0)
set(MD5_PPM_420_ISLOW_ARI_SKIP16_139 087c6b123db16ac00cb88c5b590bb74a)
- set(MD5_PPM_420_ISLOW_PROG_STRIP71_132 a7f2ba6ea335f03549888bed66a89fae)
- set(MD5_PPM_420_ISLOW_ARI_STRIP4_56 0e5e44a39b94817917a1bac72903246b)
+ set(MD5_PPM_420_ISLOW_PROG_CROP62x62_71_71 26eb36ccc7d1f0cb80cdabb0ac8b5d99)
+ set(MD5_PPM_420_ISLOW_ARI_CROP53x53_4_4 886c6775af22370257122f8b16207e6d)
set(MD5_PPM_444_ISLOW_SKIP1_6 5606f86874cf26b8fcee1117a0a436a6)
- set(MD5_PPM_444_ISLOW_PROG_STRIP13_110 40b5d9742558dca6229d7332fc2dda07)
- set(MD5_PPM_444_ISLOW_ARI_STRIP0_36 9aceb5b9449c900b892a1d2fe39351b4)
+ set(MD5_PPM_444_ISLOW_PROG_CROP98x98_13_13 db87dc7ce26bcdc7a6b56239ce2b9d6c)
+ set(MD5_PPM_444_ISLOW_ARI_CROP37x37_0_0 cb57b32bd6d03e35432362f7bf184b6d)
set(MD5_JPEG_CROP b4197f377e621c4e9b1d20471432610d)
endif()
@@ -764,22 +764,23 @@
add_test(cjpeg${suffix}-420-islow-prog
${dir}cjpeg${suffix} -dct int -prog
-outfile testout_420_islow_prog.jpg ${TESTIMAGES}/testorig.ppm)
- add_test(djpeg${suffix}-420-islow-prog-strip71_132
- ${dir}djpeg${suffix} -dct int -strip 71,132 -ppm
- -outfile testout_420_islow_strip71,132.ppm testout_420_islow_prog.jpg)
- add_test(djpeg${suffix}-420-islow-prog-strip71_132-cmp
- ${MD5CMP} ${MD5_PPM_420_ISLOW_PROG_STRIP71_132}
- testout_420_islow_strip71,132.ppm)
+ add_test(djpeg${suffix}-420-islow-prog-crop62x62_71_71
+ ${dir}djpeg${suffix} -dct int -crop 62x62+71+71 -ppm
+ -outfile testout_420_islow_prog_crop62x62,71,71.ppm
+ testout_420_islow_prog.jpg)
+ add_test(djpeg${suffix}-420-islow-prog-crop62x62_71_71-cmp
+ ${MD5CMP} ${MD5_PPM_420_ISLOW_PROG_CROP62x62_71_71}
+ testout_420_islow_prog_crop62x62,71,71.ppm)
# Context rows: Yes Intra-iMCU row: No iMCU row prefetch: No ENT: arith
if(WITH_ARITH_DEC)
- add_test(djpeg${suffix}-420-islow-ari-strip4_56
- ${dir}djpeg${suffix} -dct int -strip 4,56 -ppm
- -outfile testout_420_islow_ari_strip4,56.ppm
+ add_test(djpeg${suffix}-420-islow-ari-crop53x53_4_4
+ ${dir}djpeg${suffix} -dct int -crop 53x53+4+4 -ppm
+ -outfile testout_420_islow_ari_crop53x53,4,4.ppm
${TESTIMAGES}/testimgari.jpg)
- add_test(djpeg${suffix}-420-islow-ari-strip4_56-cmp
- ${MD5CMP} ${MD5_PPM_420_ISLOW_ARI_STRIP4_56}
- testout_420_islow_ari_strip4,56.ppm)
+ add_test(djpeg${suffix}-420-islow-ari-crop53x53_4_4-cmp
+ ${MD5CMP} ${MD5_PPM_420_ISLOW_ARI_CROP53x53_4_4}
+ testout_420_islow_ari_crop53x53,4,4.ppm)
endif()
# Context rows: No Intra-iMCU row: Yes ENT: huff
@@ -796,13 +797,13 @@
add_test(cjpeg${suffix}-444-islow-prog
${dir}cjpeg${suffix} -dct int -prog -sample 1x1
-outfile testout_444_islow_prog.jpg ${TESTIMAGES}/testorig.ppm)
- add_test(djpeg${suffix}-444-islow-prog-strip13_110
- ${dir}djpeg${suffix} -dct int -strip 13,110 -ppm
- -outfile testout_444_islow_prog_strip13,110.ppm
+ add_test(djpeg${suffix}-444-islow-prog-crop98x98_13_13
+ ${dir}djpeg${suffix} -dct int -crop 98x98+13+13 -ppm
+ -outfile testout_444_islow_prog_crop98x98,13,13.ppm
testout_444_islow_prog.jpg)
- add_test(djpeg${suffix}-444-islow-prog_strip13_110-cmp
- ${MD5CMP} ${MD5_PPM_444_ISLOW_PROG_STRIP13_110}
- testout_444_islow_prog_strip13,110.ppm)
+ add_test(djpeg${suffix}-444-islow-prog_crop98x98_13_13-cmp
+ ${MD5CMP} ${MD5_PPM_444_ISLOW_PROG_CROP98x98_13_13}
+ testout_444_islow_prog_crop98x98,13,13.ppm)
# Context rows: No Intra-iMCU row: No ENT: arith
if(WITH_ARITH_ENC)
@@ -810,13 +811,13 @@
${dir}cjpeg${suffix} -dct int -arithmetic -sample 1x1
-outfile testout_444_islow_ari.jpg ${TESTIMAGES}/testorig.ppm)
if(WITH_ARITH_DEC)
- add_test(djpeg${suffix}-444-islow-ari-strip0_36
- ${dir}djpeg${suffix} -dct int -strip 0,36 -ppm
- -outfile testout_444_islow_ari_strip0,36.ppm
+ add_test(djpeg${suffix}-444-islow-ari-crop37x37_0_0
+ ${dir}djpeg${suffix} -dct int -crop 37x37+0+0 -ppm
+ -outfile testout_444_islow_ari_crop37x37,0,0.ppm
testout_444_islow_ari.jpg)
- add_test(djpeg${suffix}-444-islow-ari-strip0_36-cmp
- ${MD5CMP} ${MD5_PPM_444_ISLOW_ARI_STRIP0_36}
- testout_444_islow_ari_strip0,36.ppm)
+ add_test(djpeg${suffix}-444-islow-ari-crop37x37_0_0-cmp
+ ${MD5CMP} ${MD5_PPM_444_ISLOW_ARI_CROP37x37_0_0}
+ testout_444_islow_ari_crop37x37,0,0.ppm)
endif()
endif()