From d2d798d0f11abcbf141db69869e76e8d123ec1eb Mon Sep 17 00:00:00 2001 From: Kirill Volinsky Date: Sat, 13 Dec 2014 20:28:24 +0000 Subject: FreeImage updated to 3.16 git-svn-id: http://svn.miranda-ng.org/main/trunk@11379 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c --- plugins/AdvaImg/src/LibJPEG/usage.txt | 47 +++++++++++++++++++++++++++-------- 1 file changed, 37 insertions(+), 10 deletions(-) (limited to 'plugins/AdvaImg/src/LibJPEG/usage.txt') diff --git a/plugins/AdvaImg/src/LibJPEG/usage.txt b/plugins/AdvaImg/src/LibJPEG/usage.txt index c8ea77cd26..ca9f7d74a4 100644 --- a/plugins/AdvaImg/src/LibJPEG/usage.txt +++ b/plugins/AdvaImg/src/LibJPEG/usage.txt @@ -158,10 +158,10 @@ file size is about the same --- often a little smaller. Switches for advanced users: - -arithmetic Use arithmetic coding. CAUTION: arithmetic coded JPEG - is not yet widely implemented, so many decoders will - be unable to view an arithmetic coded JPEG file at - all. + -arithmetic Use arithmetic coding. + CAUTION: arithmetic coded JPEG is not yet widely + implemented, so many decoders will be unable to + view an arithmetic coded JPEG file at all. -block N Set DCT block size. All N from 1 to 16 are possible. Default is 8 (baseline format). @@ -188,6 +188,25 @@ Switches for advanced users: so many decoders will be unable to view a reversible color transformed JPEG file at all. + -bgycc Create big gamut YCC JPEG file. + In this type of encoding the color difference + components are quantized further by a factor of 2 + compared to the normal Cb/Cr values, thus creating + space to allow larger color values with higher + saturation than the normal gamut limits to be encoded. + In order to compensate for the loss of color fidelity + compared to a normal YCC encoded file, the color + quantization tables can be adjusted accordingly. + For example, cjpeg -bgycc -quality 80,90 will give + similar results as cjpeg -quality 80. + CAUTION: For correct decompression a decoder with big + gamut YCC support (JFIF version 2) is required. + An old decoder may or may not display a big gamut YCC + encoded JPEG file, depending on JFIF version check + and corresponding warning/error configuration. + In case of a granted decompression the old decoder + will display the image with half saturated colors. + -dct int Use integer DCT method (default). -dct fast Use fast integer DCT (less accurate). -dct float Use floating-point DCT method. @@ -387,7 +406,8 @@ quality settings to make very small JPEG files; the percentage improvement is often a lot more than it is on larger files. (At present, -optimize mode is always selected when generating progressive JPEG files.) -GIF input files are no longer supported, to avoid the Unisys LZW patent. +GIF input files are no longer supported, to avoid the Unisys LZW patent +(now expired). (Conversion of GIF files to JPEG is usually a bad idea anyway.) @@ -415,8 +435,9 @@ it may run out of memory even with -maxmemory 0. In that case you can still decompress, with some loss of image quality, by specifying -onepass for one-pass quantization. -To avoid the Unisys LZW patent, djpeg produces uncompressed GIF files. These -are larger than they should be, but are readable by standard GIF decoders. +To avoid the Unisys LZW patent (now expired), djpeg produces uncompressed GIF +files. These are larger than they should be, but are readable by standard GIF +decoders. HINTS FOR BOTH PROGRAMS @@ -533,14 +554,20 @@ image region but losslessly preserves what is inside. Like the rotate and flip transforms, lossless crop is restricted by the current JPEG format: the upper left corner of the selected region must fall on an iMCU boundary. If this does not hold for the given crop parameters, we silently move the upper -left corner up and/or left to make it so, simultaneously increasing the region -dimensions to keep the lower right crop corner unchanged. (Thus, the output -image covers at least the requested region, but may cover more.) +left corner up and/or left to make it so, simultaneously increasing the +region dimensions to keep the lower right crop corner unchanged. (Thus, the +output image covers at least the requested region, but may cover more.) +The adjustment of the region dimensions may be optionally disabled. The image can be losslessly cropped by giving the switch: -crop WxH+X+Y Crop to a rectangular subarea of width W, height H starting at point X,Y. +A complementary lossless-wipe option is provided to discard (gray out) data +inside a given image region while losslessly preserving what is outside: + -wipe WxH+X+Y Wipe (gray out) a rectangular subarea of + width W, height H starting at point X,Y. + Other not-strictly-lossless transformation switches are: -grayscale Force grayscale output. -- cgit v1.2.3