move images.bitmap.loading to images.bitmap

db4
Doug Coleman 2010-05-01 17:11:11 -05:00
parent f67c62b0e4
commit 64b248c5d5
3 changed files with 368 additions and 370 deletions

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@ -1,4 +1,4 @@
USING: images.bitmap images.bitmap.loading images.testing kernel ;
USING: images.bitmap images.testing kernel ;
IN: images.bitmap.tests
! "vocab:images/testing/bmp/1bit.bmp" decode-test

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@ -3,19 +3,382 @@
USING: accessors alien alien.c-types arrays byte-arrays columns
combinators compression.run-length endian fry grouping images
images.loader images.normalization io io.binary
io.encodings.binary io.encodings.string io.files
io.streams.limited kernel locals macros math math.bitwise
math.functions namespaces sequences specialized-arrays
strings summary ;
io.encodings.8-bit.latin1 io.encodings.binary
io.encodings.string io.files io.streams.limited kernel locals
macros math math.bitwise math.functions namespaces sequences
specialized-arrays summary ;
QUALIFIED-WITH: bitstreams b
SPECIALIZED-ARRAYS: uint ushort ;
IN: images.bitmap
! http://www.fileformat.info/format/bmp/egff.htm
! http://www.digicamsoft.com/bmp/bmp.html
SINGLETON: bmp-image
"bmp" bmp-image register-image-class
: write2 ( n -- ) 2 >le write ;
: write4 ( n -- ) 4 >le write ;
ERROR: unknown-component-order bitmap ;
ERROR: unknown-bitmap-header n ;
: read2 ( -- n ) 2 read le> ;
: read4 ( -- n ) 4 read le> ;
TUPLE: loading-bitmap
file-header header
color-palette color-index bitfields ;
TUPLE: file-header
{ magic initial: "BM" }
{ size }
{ reserved1 initial: 0 }
{ reserved2 initial: 0 }
{ offset }
{ header-length } ;
TUPLE: v3-header
{ width initial: 0 }
{ height initial: 0 }
{ planes initial: 0 }
{ bit-count initial: 0 }
{ compression initial: 0 }
{ image-size initial: 0 }
{ x-resolution initial: 0 }
{ y-resolution initial: 0 }
{ colors-used initial: 0 }
{ colors-important initial: 0 } ;
TUPLE: v4-header < v3-header
{ red-mask initial: 0 }
{ green-mask initial: 0 }
{ blue-mask initial: 0 }
{ alpha-mask initial: 0 }
{ cs-type initial: 0 }
{ end-points initial: 0 }
{ gamma-red initial: 0 }
{ gamma-green initial: 0 }
{ gamma-blue initial: 0 } ;
TUPLE: v5-header < v4-header
{ intent initial: 0 }
{ profile-data initial: 0 }
{ profile-size initial: 0 }
{ reserved3 initial: 0 } ;
TUPLE: os2v1-header
{ width initial: 0 }
{ height initial: 0 }
{ planes initial: 0 }
{ bit-count initial: 0 } ;
TUPLE: os2v2-header < os2v1-header
{ compression initial: 0 }
{ image-size initial: 0 }
{ x-resolution initial: 0 }
{ y-resolution initial: 0 }
{ colors-used initial: 0 }
{ colors-important initial: 0 }
{ units initial: 0 }
{ reserved initial: 0 }
{ recording initial: 0 }
{ rendering initial: 0 }
{ size1 initial: 0 }
{ size2 initial: 0 }
{ color-encoding initial: 0 }
{ identifier initial: 0 } ;
UNION: v-header v3-header v4-header v5-header ;
UNION: os2-header os2v1-header os2v2-header ;
: parse-file-header ( -- file-header )
\ file-header new
2 read latin1 decode >>magic
read4 >>size
read2 >>reserved1
read2 >>reserved2
read4 >>offset
read4 >>header-length ;
: read-v3-header-data ( header -- header )
read4 >>width
read4 32 >signed >>height
read2 >>planes
read2 >>bit-count
read4 >>compression
read4 >>image-size
read4 >>x-resolution
read4 >>y-resolution
read4 >>colors-used
read4 >>colors-important ;
: read-v3-header ( -- header )
\ v3-header new
read-v3-header-data ;
: read-v4-header-data ( header -- header )
read4 >>red-mask
read4 >>green-mask
read4 >>blue-mask
read4 >>alpha-mask
read4 >>cs-type
read4 read4 read4 3array >>end-points
read4 >>gamma-red
read4 >>gamma-green
read4 >>gamma-blue ;
: read-v4-header ( -- v4-header )
\ v4-header new
read-v3-header-data
read-v4-header-data ;
: read-v5-header-data ( v5-header -- v5-header )
read4 >>intent
read4 >>profile-data
read4 >>profile-size
read4 >>reserved3 ;
: read-v5-header ( -- loading-bitmap )
\ v5-header new
read-v3-header-data
read-v4-header-data
read-v5-header-data ;
: read-os2v1-header ( -- os2v1-header )
\ os2v1-header new
read2 >>width
read2 16 >signed >>height
read2 >>planes
read2 >>bit-count ;
: read-os2v2-header-data ( os2v2-header -- os2v2-header )
read4 >>width
read4 32 >signed >>height
read2 >>planes
read2 >>bit-count
read4 >>compression
read4 >>image-size
read4 >>x-resolution
read4 >>y-resolution
read4 >>colors-used
read4 >>colors-important
read2 >>units
read2 >>reserved
read2 >>recording
read2 >>rendering
read4 >>size1
read4 >>size2
read4 >>color-encoding
read4 >>identifier ;
: read-os2v2-header ( -- os2v2-header )
\ os2v2-header new
read-os2v2-header-data ;
: parse-header ( n -- header )
{
{ 12 [ read-os2v1-header ] }
{ 64 [ read-os2v2-header ] }
{ 40 [ read-v3-header ] }
{ 108 [ read-v4-header ] }
{ 124 [ read-v5-header ] }
[ unknown-bitmap-header ]
} case ;
: color-index-length ( header -- n )
{
[ width>> ]
[ planes>> * ]
[ bit-count>> * 31 + 32 /i 4 * ]
[ height>> abs * ]
} cleave ;
: color-palette-length ( loading-bitmap -- n )
file-header>>
[ offset>> 14 - ] [ header-length>> ] bi - ;
: parse-color-palette ( loading-bitmap -- loading-bitmap )
dup color-palette-length read >>color-palette ;
GENERIC: parse-color-data* ( loading-bitmap header -- loading-bitmap )
: parse-color-data ( loading-bitmap -- loading-bitmap )
dup header>> parse-color-data* ;
M: os2v1-header parse-color-data* ( loading-bitmap header -- loading-bitmap )
color-index-length read >>color-index ;
M: object parse-color-data* ( loading-bitmap header -- loading-bitmap )
dup image-size>> [ 0 ] unless* dup 0 >
[ nip ] [ drop color-index-length ] if read >>color-index ;
: alpha-used? ( loading-bitmap -- ? )
color-index>> 4 <sliced-groups> [ fourth 0 = ] all? not ;
GENERIC: bitmap>component-order* ( loading-bitmap header -- object )
: bitmap>component-order ( loading-bitmap -- object )
dup header>> bitmap>component-order* ;
: simple-bitmap>component-order ( loading-bitamp -- object )
header>> bit-count>> {
{ 32 [ BGRX ] }
{ 24 [ BGR ] }
{ 16 [ BGR ] }
{ 8 [ BGR ] }
{ 4 [ BGR ] }
{ 1 [ BGR ] }
[ unknown-component-order ]
} case ;
: advanced-bitmap>component-order ( loading-bitmap -- object )
[ ] [ header>> bit-count>> ] [ alpha-used? ] tri 2array {
{ { 32 t } [ drop BGRA ] }
{ { 32 f } [ drop BGRX ] }
[ drop simple-bitmap>component-order ]
} case ;
: color-lookup3 ( loading-bitmap -- seq )
[ color-index>> >array ]
[ color-palette>> 3 <sliced-groups> ] bi
'[ _ nth ] map concat ;
: color-lookup4 ( loading-bitmap -- seq )
[ color-index>> >array ]
[ color-palette>> 4 <sliced-groups> [ 3 head-slice ] map ] bi
'[ _ nth ] map concat ;
! os2v1 is 3bytes each, all others are 3 + 1 unused
: color-lookup ( loading-bitmap -- seq )
dup file-header>> header-length>> {
{ 12 [ color-lookup3 ] }
{ 64 [ color-lookup4 ] }
{ 40 [ color-lookup4 ] }
{ 108 [ color-lookup4 ] }
{ 124 [ color-lookup4 ] }
} case ;
M: os2v1-header bitmap>component-order* drop simple-bitmap>component-order ;
M: os2v2-header bitmap>component-order* drop simple-bitmap>component-order ;
M: v3-header bitmap>component-order* drop simple-bitmap>component-order ;
M: v4-header bitmap>component-order* drop advanced-bitmap>component-order ;
M: v5-header bitmap>component-order* drop advanced-bitmap>component-order ;
: uncompress-bitfield ( seq masks -- bytes' )
'[
_ [
[ bitand ] [ bit-count ] [ log2 ] tri - shift
] with map
] { } map-as B{ } concat-as ;
ERROR: bmp-not-supported n ;
: bitmap>bytes ( loading-bitmap -- byte-array )
dup header>> bit-count>>
{
{ 32 [ color-index>> ] }
{ 24 [ color-index>> ] }
{ 16 [
[
! byte-array>ushort-array
2 group [ le> ] map
! 5 6 5
! { HEX: f800 HEX: 7e0 HEX: 1f } uncompress-bitfield
! 5 5 5
{ HEX: 7c00 HEX: 3e0 HEX: 1f } uncompress-bitfield
] change-color-index
color-index>>
] }
{ 8 [ color-lookup ] }
{ 4 [ [ 4 b:byte-array-n>seq ] change-color-index color-lookup ] }
{ 1 [ [ 1 b:byte-array-n>seq ] change-color-index color-lookup ] }
[ bmp-not-supported ]
} case >byte-array ;
: set-bitfield-widths ( loading-bitmap -- loading-bitmap' )
dup header>> bit-count>> {
{ 16 [ dup color-palette>> 4 group [ le> ] map ] }
{ 32 [ { HEX: ff0000 HEX: ff00 HEX: ff } ] }
} case reverse >>bitfields ;
ERROR: unsupported-bitfield-widths n ;
M: unsupported-bitfield-widths summary
drop "Bitmaps only support bitfield compression in 16/32bit images" ;
: uncompress-bitfield-widths ( loading-bitmap -- loading-bitmap' )
set-bitfield-widths
dup header>> bit-count>> {
{ 16 [
dup bitfields>> '[
byte-array>ushort-array _ uncompress-bitfield
] change-color-index
] }
{ 32 [ ] }
[ unsupported-bitfield-widths ]
} case ;
ERROR: unsupported-bitmap-compression compression ;
GENERIC: uncompress-bitmap* ( loading-bitmap header -- loading-bitmap )
: uncompress-bitmap ( loading-bitmap -- loading-bitmap )
dup header>> uncompress-bitmap* ;
M: os2-header uncompress-bitmap* ( loading-bitmap header -- loading-bitmap' )
drop ;
: do-run-length-uncompress ( loading-bitmap word -- loading-bitmap )
dupd '[
_ header>> [ width>> ] [ height>> ] bi
_ execute
] change-color-index ; inline
M: v-header uncompress-bitmap* ( loading-bitmap header -- loading-bitmap' )
compression>> {
{ f [ ] }
{ 0 [ ] }
{ 1 [ \ run-length-uncompress-bitmap8 do-run-length-uncompress ] }
{ 2 [ \ run-length-uncompress-bitmap4 do-run-length-uncompress ] }
{ 3 [ uncompress-bitfield-widths ] }
{ 4 [ "jpeg" unsupported-bitmap-compression ] }
{ 5 [ "png" unsupported-bitmap-compression ] }
} case ;
ERROR: unsupported-bitmap-file magic ;
: load-bitmap ( stream -- loading-bitmap )
[
\ loading-bitmap new
parse-file-header [ >>file-header ] [ ] bi magic>> {
{ "BM" [
dup file-header>> header-length>> parse-header >>header
parse-color-palette
parse-color-data
] }
! { "BA" [ parse-os2-bitmap-array ] }
! { "CI" [ parse-os2-color-icon ] }
! { "CP" [ parse-os2-color-pointer ] }
! { "IC" [ parse-os2-icon ] }
! { "PT" [ parse-os2-pointer ] }
[ unsupported-bitmap-file ]
} case
] with-input-stream ;
: loading-bitmap>bytes ( loading-bitmap -- byte-array )
uncompress-bitmap bitmap>bytes ;
M: bmp-image stream>image ( stream bmp-image -- bitmap )
drop load-bitmap
[ image new ] dip
{
[ loading-bitmap>bytes >>bitmap ]
[ header>> [ width>> ] [ height>> abs ] bi 2array >>dim ]
[ header>> height>> 0 < not >>upside-down? ]
[ bitmap>component-order >>component-order ubyte-components >>component-type ]
} cleave ;
: output-width-and-height ( image -- )
[ dim>> first write4 ]
[

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@ -5,368 +5,3 @@ compression.run-length fry grouping images images.loader io
io.binary io.encodings.binary
io.encodings.string io.streams.limited kernel math math.bitwise
io.encodings.8-bit.latin1 sequences specialized-arrays summary images.bitmap ;
QUALIFIED-WITH: bitstreams b
SPECIALIZED-ARRAY: ushort
IN: images.bitmap.loading
! http://www.fileformat.info/format/bmp/egff.htm
! http://www.digicamsoft.com/bmp/bmp.html
ERROR: unknown-component-order bitmap ;
ERROR: unknown-bitmap-header n ;
: read2 ( -- n ) 2 read le> ;
: read4 ( -- n ) 4 read le> ;
TUPLE: loading-bitmap
file-header header
color-palette color-index bitfields ;
TUPLE: file-header
{ magic initial: "BM" }
{ size }
{ reserved1 initial: 0 }
{ reserved2 initial: 0 }
{ offset }
{ header-length } ;
TUPLE: v3-header
{ width initial: 0 }
{ height initial: 0 }
{ planes initial: 0 }
{ bit-count initial: 0 }
{ compression initial: 0 }
{ image-size initial: 0 }
{ x-resolution initial: 0 }
{ y-resolution initial: 0 }
{ colors-used initial: 0 }
{ colors-important initial: 0 } ;
TUPLE: v4-header < v3-header
{ red-mask initial: 0 }
{ green-mask initial: 0 }
{ blue-mask initial: 0 }
{ alpha-mask initial: 0 }
{ cs-type initial: 0 }
{ end-points initial: 0 }
{ gamma-red initial: 0 }
{ gamma-green initial: 0 }
{ gamma-blue initial: 0 } ;
TUPLE: v5-header < v4-header
{ intent initial: 0 }
{ profile-data initial: 0 }
{ profile-size initial: 0 }
{ reserved3 initial: 0 } ;
TUPLE: os2v1-header
{ width initial: 0 }
{ height initial: 0 }
{ planes initial: 0 }
{ bit-count initial: 0 } ;
TUPLE: os2v2-header < os2v1-header
{ compression initial: 0 }
{ image-size initial: 0 }
{ x-resolution initial: 0 }
{ y-resolution initial: 0 }
{ colors-used initial: 0 }
{ colors-important initial: 0 }
{ units initial: 0 }
{ reserved initial: 0 }
{ recording initial: 0 }
{ rendering initial: 0 }
{ size1 initial: 0 }
{ size2 initial: 0 }
{ color-encoding initial: 0 }
{ identifier initial: 0 } ;
UNION: v-header v3-header v4-header v5-header ;
UNION: os2-header os2v1-header os2v2-header ;
: parse-file-header ( -- file-header )
\ file-header new
2 read latin1 decode >>magic
read4 >>size
read2 >>reserved1
read2 >>reserved2
read4 >>offset
read4 >>header-length ;
: read-v3-header-data ( header -- header )
read4 >>width
read4 32 >signed >>height
read2 >>planes
read2 >>bit-count
read4 >>compression
read4 >>image-size
read4 >>x-resolution
read4 >>y-resolution
read4 >>colors-used
read4 >>colors-important ;
: read-v3-header ( -- header )
\ v3-header new
read-v3-header-data ;
: read-v4-header-data ( header -- header )
read4 >>red-mask
read4 >>green-mask
read4 >>blue-mask
read4 >>alpha-mask
read4 >>cs-type
read4 read4 read4 3array >>end-points
read4 >>gamma-red
read4 >>gamma-green
read4 >>gamma-blue ;
: read-v4-header ( -- v4-header )
\ v4-header new
read-v3-header-data
read-v4-header-data ;
: read-v5-header-data ( v5-header -- v5-header )
read4 >>intent
read4 >>profile-data
read4 >>profile-size
read4 >>reserved3 ;
: read-v5-header ( -- loading-bitmap )
\ v5-header new
read-v3-header-data
read-v4-header-data
read-v5-header-data ;
: read-os2v1-header ( -- os2v1-header )
\ os2v1-header new
read2 >>width
read2 16 >signed >>height
read2 >>planes
read2 >>bit-count ;
: read-os2v2-header-data ( os2v2-header -- os2v2-header )
read4 >>width
read4 32 >signed >>height
read2 >>planes
read2 >>bit-count
read4 >>compression
read4 >>image-size
read4 >>x-resolution
read4 >>y-resolution
read4 >>colors-used
read4 >>colors-important
read2 >>units
read2 >>reserved
read2 >>recording
read2 >>rendering
read4 >>size1
read4 >>size2
read4 >>color-encoding
read4 >>identifier ;
: read-os2v2-header ( -- os2v2-header )
\ os2v2-header new
read-os2v2-header-data ;
: parse-header ( n -- header )
{
{ 12 [ read-os2v1-header ] }
{ 64 [ read-os2v2-header ] }
{ 40 [ read-v3-header ] }
{ 108 [ read-v4-header ] }
{ 124 [ read-v5-header ] }
[ unknown-bitmap-header ]
} case ;
: color-index-length ( header -- n )
{
[ width>> ]
[ planes>> * ]
[ bit-count>> * 31 + 32 /i 4 * ]
[ height>> abs * ]
} cleave ;
: color-palette-length ( loading-bitmap -- n )
file-header>>
[ offset>> 14 - ] [ header-length>> ] bi - ;
: parse-color-palette ( loading-bitmap -- loading-bitmap )
dup color-palette-length read >>color-palette ;
GENERIC: parse-color-data* ( loading-bitmap header -- loading-bitmap )
: parse-color-data ( loading-bitmap -- loading-bitmap )
dup header>> parse-color-data* ;
M: os2v1-header parse-color-data* ( loading-bitmap header -- loading-bitmap )
color-index-length read >>color-index ;
M: object parse-color-data* ( loading-bitmap header -- loading-bitmap )
dup image-size>> [ 0 ] unless* dup 0 >
[ nip ] [ drop color-index-length ] if read >>color-index ;
: alpha-used? ( loading-bitmap -- ? )
color-index>> 4 <sliced-groups> [ fourth 0 = ] all? not ;
GENERIC: bitmap>component-order* ( loading-bitmap header -- object )
: bitmap>component-order ( loading-bitmap -- object )
dup header>> bitmap>component-order* ;
: simple-bitmap>component-order ( loading-bitamp -- object )
header>> bit-count>> {
{ 32 [ BGRX ] }
{ 24 [ BGR ] }
{ 16 [ BGR ] }
{ 8 [ BGR ] }
{ 4 [ BGR ] }
{ 1 [ BGR ] }
[ unknown-component-order ]
} case ;
: advanced-bitmap>component-order ( loading-bitmap -- object )
[ ] [ header>> bit-count>> ] [ alpha-used? ] tri 2array {
{ { 32 t } [ drop BGRA ] }
{ { 32 f } [ drop BGRX ] }
[ drop simple-bitmap>component-order ]
} case ;
: color-lookup3 ( loading-bitmap -- seq )
[ color-index>> >array ]
[ color-palette>> 3 <sliced-groups> ] bi
'[ _ nth ] map concat ;
: color-lookup4 ( loading-bitmap -- seq )
[ color-index>> >array ]
[ color-palette>> 4 <sliced-groups> [ 3 head-slice ] map ] bi
'[ _ nth ] map concat ;
! os2v1 is 3bytes each, all others are 3 + 1 unused
: color-lookup ( loading-bitmap -- seq )
dup file-header>> header-length>> {
{ 12 [ color-lookup3 ] }
{ 64 [ color-lookup4 ] }
{ 40 [ color-lookup4 ] }
{ 108 [ color-lookup4 ] }
{ 124 [ color-lookup4 ] }
} case ;
M: os2v1-header bitmap>component-order* drop simple-bitmap>component-order ;
M: os2v2-header bitmap>component-order* drop simple-bitmap>component-order ;
M: v3-header bitmap>component-order* drop simple-bitmap>component-order ;
M: v4-header bitmap>component-order* drop advanced-bitmap>component-order ;
M: v5-header bitmap>component-order* drop advanced-bitmap>component-order ;
: uncompress-bitfield ( seq masks -- bytes' )
'[
_ [
[ bitand ] [ bit-count ] [ log2 ] tri - shift
] with map
] { } map-as B{ } concat-as ;
ERROR: bmp-not-supported n ;
: bitmap>bytes ( loading-bitmap -- byte-array )
dup header>> bit-count>>
{
{ 32 [ color-index>> ] }
{ 24 [ color-index>> ] }
{ 16 [
[
! byte-array>ushort-array
2 group [ le> ] map
! 5 6 5
! { HEX: f800 HEX: 7e0 HEX: 1f } uncompress-bitfield
! 5 5 5
{ HEX: 7c00 HEX: 3e0 HEX: 1f } uncompress-bitfield
] change-color-index
color-index>>
] }
{ 8 [ color-lookup ] }
{ 4 [ [ 4 b:byte-array-n>seq ] change-color-index color-lookup ] }
{ 1 [ [ 1 b:byte-array-n>seq ] change-color-index color-lookup ] }
[ bmp-not-supported ]
} case >byte-array ;
: set-bitfield-widths ( loading-bitmap -- loading-bitmap' )
dup header>> bit-count>> {
{ 16 [ dup color-palette>> 4 group [ le> ] map ] }
{ 32 [ { HEX: ff0000 HEX: ff00 HEX: ff } ] }
} case reverse >>bitfields ;
ERROR: unsupported-bitfield-widths n ;
M: unsupported-bitfield-widths summary
drop "Bitmaps only support bitfield compression in 16/32bit images" ;
: uncompress-bitfield-widths ( loading-bitmap -- loading-bitmap' )
set-bitfield-widths
dup header>> bit-count>> {
{ 16 [
dup bitfields>> '[
byte-array>ushort-array _ uncompress-bitfield
] change-color-index
] }
{ 32 [ ] }
[ unsupported-bitfield-widths ]
} case ;
ERROR: unsupported-bitmap-compression compression ;
GENERIC: uncompress-bitmap* ( loading-bitmap header -- loading-bitmap )
: uncompress-bitmap ( loading-bitmap -- loading-bitmap )
dup header>> uncompress-bitmap* ;
M: os2-header uncompress-bitmap* ( loading-bitmap header -- loading-bitmap' )
drop ;
: do-run-length-uncompress ( loading-bitmap word -- loading-bitmap )
dupd '[
_ header>> [ width>> ] [ height>> ] bi
_ execute
] change-color-index ; inline
M: v-header uncompress-bitmap* ( loading-bitmap header -- loading-bitmap' )
compression>> {
{ f [ ] }
{ 0 [ ] }
{ 1 [ \ run-length-uncompress-bitmap8 do-run-length-uncompress ] }
{ 2 [ \ run-length-uncompress-bitmap4 do-run-length-uncompress ] }
{ 3 [ uncompress-bitfield-widths ] }
{ 4 [ "jpeg" unsupported-bitmap-compression ] }
{ 5 [ "png" unsupported-bitmap-compression ] }
} case ;
ERROR: unsupported-bitmap-file magic ;
: load-bitmap ( stream -- loading-bitmap )
[
\ loading-bitmap new
parse-file-header [ >>file-header ] [ ] bi magic>> {
{ "BM" [
dup file-header>> header-length>> parse-header >>header
parse-color-palette
parse-color-data
] }
! { "BA" [ parse-os2-bitmap-array ] }
! { "CI" [ parse-os2-color-icon ] }
! { "CP" [ parse-os2-color-pointer ] }
! { "IC" [ parse-os2-icon ] }
! { "PT" [ parse-os2-pointer ] }
[ unsupported-bitmap-file ]
} case
] with-input-stream ;
: loading-bitmap>bytes ( loading-bitmap -- byte-array )
uncompress-bitmap bitmap>bytes ;
M: bmp-image stream>image ( stream bmp-image -- bitmap )
drop load-bitmap
[ image new ] dip
{
[ loading-bitmap>bytes >>bitmap ]
[ header>> [ width>> ] [ height>> abs ] bi 2array >>dim ]
[ header>> height>> 0 < not >>upside-down? ]
[ bitmap>component-order >>component-order ubyte-components >>component-type ]
} cleave ;