• Bug#266491: netpbm: giftopnm produces incorrect alpha map (1/2)

    From Nigel Williams@1:229/2 to All on Wed Aug 18 03:00:13 2004
    From: [email protected]

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    Package: netpbm
    Version: 2:10.0-5
    Severity: normal
    Tags: patch

    giftopnm generates an alpha map based on pixel colour, not on the colourmap index of that pixel. e.g. the colourmap contains two entries, both with RGB 0/0/0. The Gif89a header says that one of them is transparent. giftopnm will mark pixels using both of those colourmap indices as transparent.

    -- System Information:
    Debian Release: 3.1
    APT prefers unstable
    APT policy: (500, 'unstable')
    Architecture: i386 (i686)
    Kernel: Linux 2.6.7-broadsword
    Locale: LANG=C, LC_CTYPE=C

    Versions of packages netpbm depends on:
    ii bc 1.06-15 The GNU bc arbitrary precision cal ii libc6 2.3.2.ds1-13 GNU C Library: Shared libraries an ii libjpeg62 6b-9 The Independent JPEG Group's JPEG ii libnetpbm10 2:10.0-5 Shared libraries for netpbm
    ii libpng12-0 1.2.5.0-6 PNG library - runtime
    ii libtiff4 3.6.1-1.1 Tag Image File Format library
    ii zlib1g 1:1.2.1.1-5 compression library - runtime

    -- no debconf information

    diff -r -u3 netpbm-free-9.20/compile.h netpbm-free-9.20-gif-alpha-fix/compile.h --- netpbm-free-9.20/compile.h Tue Aug 17 06:35:15 2004
    +++ netpbm-free-9.20-gif-alpha-fix/compile.h Tue Aug 17 06:07:46 2004
    @@ -1,4 +1,4 @@
    /* compile_time.h This file tells the package when it was compiled */
    /* DO NOT EDIT - THIS FILE IS MAINTAINED AUTOMATICALLY */ -#define COMPILE_TIME "Sun Mar 17 08:28:09 GMT 2002"
    -#define COMPILED_BY "steve"
    +#define COMPILE_TIME "Tue Aug 17 06:07:46 UTC 2004"
    +#define COMPILED_BY "webnd"
    Only in netpbm-free-9.20: netpbm
    diff -r -u3 netpbm-free-9.20/pnm/giftopnm.c netpbm-free-9.20-gif-alpha-fix/pnm/giftopnm.c
    --- netpbm-free-9.20/pnm/giftopnm.c Sun Oct 7 21:09:35 2001
    +++ netpbm-free-9.20-gif-alpha-fix/pnm/giftopnm.c Tue Aug 17 06:07:38 2004
    @@ -524,7 +524,7 @@


    static void
    -ReadImage(FILE *fd, pixel ** const image, const int len, const int height, +ReadImage(FILE *fd, pixel ** const image, bit ** const alpha, const int len, const int height,
    unsigned char cmap[3][MAXCOLORMAPSIZE], const int interlace) {

    unsi