x/image/bmp: unsupported BMP image #27767

electricface · 2018-09-20T02:48:29Z

Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (`go version`)?

go version go1.11 linux/amd64

Does this issue reproduce with the latest release?

yes

What operating system and processor architecture are you using (`go env`)?

GOOS="linux"
GOARCH="amd64"

What did you do?

If possible, provide a recipe for reproducing the error.
A complete runnable program is good.
A link on play.golang.org is best.

package main

import (
	"image"
	"log"
	"os"

	_ "golang.org/x/image/bmp"
)

func main() {
	f, err := os.Open("/path/to/desktop.bmp")
	if err != nil {
		log.Fatal(err)
	}
	img, str, err := image.Decode(f)
	if err != nil {
		log.Fatal(err)
	}
	log.Println(img, str)
}

What did you expect to see?

exit code is 0

What did you see instead?

2018/09/20 10:45:39 bmp: unsupported BMP image
exit status 1

Because github does not support bmp, package bmp image files into compressed files.
desktop.bmp.tar.gz

The text was updated successfully, but these errors were encountered:

yorelog · 2018-09-21T10:35:03Z

the implement of bmp reader Package golang.org/x/image/bmp shows that bitmap info header size is fixed to 40, while the header size can set by file header.

func decodeConfig(r io.Reader) (config image.Config, bitsPerPixel int, topDown bool, err error) {
	// We only support those BMP images that are a BITMAPFILEHEADER
	// immediately followed by a BITMAPINFOHEADER.
	const (
		fileHeaderLen = 14
		infoHeaderLen = 40
	)
	var b [1024]byte
	if _, err := io.ReadFull(r, b[:fileHeaderLen+infoHeaderLen]); err != nil {
		return image.Config{}, 0, false, err
	}
	if string(b[:2]) != "BM" {
		return image.Config{}, 0, false, errors.New("bmp: invalid format")
	}
	offset := readUint32(b[10:14])
	if readUint32(b[14:18]) != infoHeaderLen {
		return image.Config{}, 0, false, ErrUnsupported
	}

so, maybe we can implement the reader like this

func decodeConfig(r io.Reader) (config image.Config, bitsPerPixel int, topDown bool, err error) {
    // We only support those BMP images that are a BITMAPFILEHEADER
    // immediately followed by a BITMAPINFOHEADER.
    const (
        fileHeaderLen = 14
    )
    var infoHeaderLen uint32 = 40 // infoHeaderLen can be a variable
    var b [1024]byte
    if _, err := io.ReadFull(r, b[:fileHeaderLen+infoHeaderLen]); err != nil {
        return image.Config{}, 0, false, err
    }
    if string(b[:2]) != "BM" {
        return image.Config{}, 0, false, errors.New("bmp: invalid format")
    }
    offset := readUint32(b[10:14])
    infoHeaderLen = readUint32(b[14:18]) // set infoHeaderLen from file header other than force compare with 40

bcmills · 2018-09-22T03:31:33Z

CC @nigeltao

nigeltao · 2018-09-26T07:11:19Z

Yeah, x/image/bmp needs to speak more versions of the BMP file format.

I don't have a lot of spare time to look at this soon, but if anybody else wants to have a crack, here's a couple of spec-like documents:

http://www.digicamsoft.com/bmp/bmp.html
https://www.fileformat.info/format/bmp/egff.htm

Translating from Win32 to Go types:
SHORT = int16
LONG = int32
BYTE = uint8
WORD = uint16
DWORD = uint32

yorelog · 2018-09-26T07:23:10Z

Yeah, x/image/bmp needs to speak more versions of the BMP file format.

I don't have a lot of spare time to look at this soon, but if anybody else wants to have a crack, here's a couple of spec-like documents:

http://www.digicamsoft.com/bmp/bmp.html
https://www.fileformat.info/format/bmp/egff.htm

Translating from Win32 to Go types:
SHORT = int16
LONG = int32
BYTE = uint8
WORD = uint16
DWORD = uint32

Thanks, I 'll give a try.

gopherbot · 2018-10-12T13:13:44Z

Change https://golang.org/cl/141799 mentions this issue: image/bmp: support v4 and v5 info header versions

mlesniak · 2018-10-19T11:35:51Z

@yorelog Any progress? You haven't assigned yourself. If you are not actively working on it, I might give it a try, too ;-)

yorelog · 2018-10-19T11:55:10Z

@mlesniak try it please . I don’t have spare time this days . But it seems someone else have this issue fixed .
Also, you can compare this with Pillow package (python ) to improve it .
Sorry for the inactive

mlesniak · 2018-10-19T12:20:29Z

@yorelog

But it seems someone else have this issue fixed .

Hmmm, did not found anything on this. Do you have any existing issue where the fix is described?

yorelog · 2018-10-20T02:47:01Z

Change https://golang.org/cl/141799 mentions this issue: image/bmp: support v4 and v5 info header versions

@mlesniak

Decode BITMAPV4INFOHEADER and BITMAPV5INFOHEADER in addition to BITMAPINFOHEADER and check if any of their features are used. If this is not the case, the bmp can be decoded as if it had the BITMAPINFOHEADER. Otherwise an ErrUnsupported is returned. The colormap.bmp and yellow_rose-small-v5.bmp files were generated using imagemagick using the following conversions: convert video-001.bmp -depth 8 -palette colormap.bmp convert yellow_rose-small.bmp -format BMP5 yellow_rose-small-v5.bmp The corresponding png files were created using imagemagick convert without any arguments. Fixes golang/go#27767 Change-Id: I5c0138b231c68132d39a29c71b61faa546921511 Reviewed-on: https://go-review.googlesource.com/c/141799 Reviewed-by: Nigel Tao <nigeltao@golang.org> Run-TryBot: Nigel Tao <nigeltao@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>

gopherbot added this to the Unreleased milestone Sep 20, 2018

bcmills added the NeedsInvestigation label Sep 22, 2018

bradfitz changed the title ~~x/image/bmp bmp: unsupported BMP image~~ x/image/bmp: unsupported BMP image Sep 25, 2018

bcmills added help wanted NeedsFix labels Sep 26, 2018

gopherbot removed the NeedsInvestigation label Sep 26, 2018

gopherbot closed this as completed in golang/image@a9455cf Oct 23, 2018

golang locked and limited conversation to collaborators Oct 23, 2019

gopherbot added the FrozenDueToAge label Oct 23, 2019

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x/image/bmp: unsupported BMP image #27767

x/image/bmp: unsupported BMP image #27767

electricface commented Sep 20, 2018

yorelog commented Sep 21, 2018

bcmills commented Sep 22, 2018

nigeltao commented Sep 26, 2018

yorelog commented Sep 26, 2018

gopherbot commented Oct 12, 2018

mlesniak commented Oct 19, 2018

yorelog commented Oct 19, 2018

mlesniak commented Oct 19, 2018

yorelog commented Oct 20, 2018

x/image/bmp: unsupported BMP image #27767

x/image/bmp: unsupported BMP image #27767

Comments

electricface commented Sep 20, 2018

What version of Go are you using (go version)?

Does this issue reproduce with the latest release?

What operating system and processor architecture are you using (go env)?

What did you do?

What did you expect to see?

What did you see instead?

yorelog commented Sep 21, 2018

bcmills commented Sep 22, 2018

nigeltao commented Sep 26, 2018

yorelog commented Sep 26, 2018

gopherbot commented Oct 12, 2018

mlesniak commented Oct 19, 2018

yorelog commented Oct 19, 2018

mlesniak commented Oct 19, 2018

yorelog commented Oct 20, 2018

What version of Go are you using (`go version`)?

What operating system and processor architecture are you using (`go env`)?