This change addresses an integer underflow appearing only on systems
using a 32-bit int type. The patch addresses the problem by limiting the
length of unknown chunks to 0x7fffffff. This value appears to already be
checked for when parsing other chunk types, so the bug shouldn't appear
elsewhere in the package. The PNG spec recommends the maximum size for
any chunk to remain under 2^31, so this shouldn't cause errors with
valid images.
Fixes#12687
Change-Id: I17f0e1683515532c661cf2b0b2bc65309d1b7bb7
Reviewed-on: https://go-review.googlesource.com/14766
Reviewed-by: Nigel Tao <nigeltao@golang.org>
http://www.w3.org/TR/PNG/#11IHDR says that "Zero is an invalid value".
This change only affects the decoder. The encoder already checks
non-positive instead of negative.
Fixes#12545.
Change-Id: Iba40e1a2f4e0eec8b2fbcd3bbdae886311434da7
Reviewed-on: https://go-review.googlesource.com/14411
Reviewed-by: Rob Pike <r@golang.org>
We could undoubtedly squeeze even more out of these loops, and in the
long term, a better compiler would be smarter with bounds checks, but in
the short term, this small change is an easy win.
benchmark old ns/op new ns/op delta
BenchmarkFillOver-8 1619470 1323192 -18.29%
BenchmarkCopyOver-8 1129369 1062787 -5.90%
BenchmarkGlyphOver-8 420070 378608 -9.87%
On github.com/golang/freetype/truetype's BenchmarkDrawString:
benchmark old ns/op new ns/op delta
BenchmarkDrawString-8 9561435 8807019 -7.89%
Change-Id: Ib1c6271ac18bced85e0fb5ebf250dd57d7747e75
Reviewed-on: https://go-review.googlesource.com/14093
Reviewed-by: Rob Pike <r@golang.org>
Before, calling the RGBA method of YCbCr color would return red values
in the range [0x0080, 0xff80]. After, the range is [0x0000, 0xffff] and
is consistent with what Gray colors' RGBA method returns. In particular,
pure black, pure white and every Gray color in between are now exactly
representable as a YCbCr color.
This fixes a regression from Go 1.4 (where YCbCr{0x00, 0x80, 0x80} was
no longer equivalent to pure black), introduced by golang.org/cl/8073 in
the Go 1.5 development cycle. In Go 1.4, the +0x80 rounding was not
noticable when Cb == 0x80 && Cr == 0x80, because the YCbCr to RGBA
conversion truncated to 8 bits before multiplying by 0x101, so the
output range was [0x0000, 0xffff].
The TestYCbCrRoundtrip fuzzy-match tolerance grows from 1 to 2 because
the YCbCr to RGB conversion now maps to an ever-so-slightly larger
range, along with the usual imprecision of accumulating rounding errors.
Also s/int/int32/ in ycbcr.go. The conversion shouldn't overflow either
way, as int is always at least 32 bits, but it does make it clearer that
the computation doesn't depend on sizeof(int).
Fixes#11691
Change-Id: I538ca0adf7e040fa96c5bc8b3aef4454535126b9
Reviewed-on: https://go-review.googlesource.com/12220
Reviewed-by: Rob Pike <r@golang.org>
This rolls back most of golang.org/cl/8841, aka 2f98bac310, and makes a
different fix. It keeps the TestTruncatedSOSDataDoesntPanic test
introduced by that other CL, which obviously still passes after this CL.
Fixes#11650, a regression (introduced by cl/8841) from Go 1.4.
The original cl/8841 changed the image/jpeg not to panic on an input
given in #10387. We still do not panic on that input, after this CL.
I have a corpus of over 160,000 JPEG images, a sample of a web crawl.
The image/jpeg code ran happily over that whole corpus both before and
after this CL, although that corpus clearly didn't catch the regression
in the first place.
This code was otherwise tested manually. I don't think that it's trivial
to synthesize a JPEG input that happens to run out of Huffman data at
just the right place. The test image attached to #11650 obviously has
that property, but I don't think we can simply add that test image to
the repository: it's 227KiB, and I don't know its copyright status.
I also looked back over the issue tracker for problematic JPEGs that
people have filed. The Go code, after this CL, is still happy on these
files in my directory:
issue2362a.jpeg
issue3916.jpeg
issue3976.jpeg
issue4084.jpeg
issue4259.jpeg
issue4291.jpeg
issue4337.jpeg
issue4500.jpeg
issue4705.jpeg
issue4975.jpeg
issue5112.jpeg
issue6767.jpeg
issue9888.jpeg
issue10133.jpeg
issue10357.jpeg
issue10447.jpeg
issue11648.jpeg
issue11650.jpeg
There were other images attached in the issue tracker that aren't
actually valid JPEGs. They failed both before and after this CL:
broken-issue2362b.jpeg
broken-issue6450.jpeg
broken-issue8693.jpeg
broken-issue10154.jpeg
broken-issue10387.jpeg
broken-issue10388.jpeg
broken-issue10389.jpeg
broken-issue10413.jpeg
In summary, this CL fixes#11650 and, after some automated and manual
testing, I don't think introduces new regressions.
Change-Id: I30b67036e9b087f3051d57dac7ea05fb4fa36f66
Reviewed-on: https://go-review.googlesource.com/12163
Reviewed-by: Rob Pike <r@golang.org>
The one in misc/makerelease/makerelease.go is particularly bad and
probably warrants rotating our keys.
I didn't update old weekly notes, and reverted some changes involving
test code for now, since we're late in the Go 1.5 freeze. Otherwise,
the rest are all auto-generated changes, and all manually reviewed.
Change-Id: Ia2753576ab5d64826a167d259f48a2f50508792d
Reviewed-on: https://go-review.googlesource.com/12048
Reviewed-by: Rob Pike <r@golang.org>
The second (fallback) draw is a no-op, but it's a non-trivial amount of work.
Fixes#11550.
benchmark old ns/op new ns/op delta
BenchmarkPaletted-4 16301219 7309568 -55.16%
Change-Id: Ic88c537b2b0c710cf517888f3dd15cb702dd142f
Reviewed-on: https://go-review.googlesource.com/11858
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
It was otherwise not being preserved across
specific Decode->Encode->Decode calls.
Fixes#11287
Change-Id: I40602da7fa39ec67403bed52ff403f361c6171bb
Reviewed-on: https://go-review.googlesource.com/11256
Reviewed-by: Nigel Tao <nigeltao@golang.org>
These tests were broken by https://go-review.googlesource.com/#/c/11227/
which fixed the LZW encoder to reject invalid input.
For TestNoPalette, the LZW encoder with a litWidth of 2 now rejects an
input byte of 128, so we change 128 to 3, as 3 <= (1<<2 - 1).
For TestPixelOutsidePaletteRange, the LZW encoder similarly rejects an
input byte of 255. Prior to golang.org/cl/11227, the encoder (again with
a litWidth of 2) accepted the 255 input byte, but masked it with (1<<2 -
1), so that the 255 test case was effectively the same as the 3 test
case. After that LZW CL, the 255 input byte is simply invalid, so we
remove it as a test case. The test still tests pixels outside of the
palette range, since 3 >= the length of the global palette, which is 2.
Change-Id: I50be9623ace016740e34801549c15f83671103eb
Reviewed-on: https://go-review.googlesource.com/11273
Reviewed-by: David Symonds <dsymonds@golang.org>
A frame that tries to use the global palette when it has
not been given should result in an error, not an image
with no palette at all.
Fixes#11150.
Change-Id: If0c3a201a0ac977eee2b7a5dc68930c0c5787f40
Reviewed-on: https://go-review.googlesource.com/11064
Reviewed-by: Nigel Tao <nigeltao@golang.org>
isn't (0, 0).
Also fix a s/b.Min.X/b.Max.X/ typo in bounds checking.
Fixes#10676
Change-Id: Ie5ff7ec20ca30367a8e65d32061959a2d8e089e9
Reviewed-on: https://go-review.googlesource.com/9712
Reviewed-by: Rob Pike <r@golang.org>
global color table.
Change-Id: Ia38f75708ed5e5b430680a1eecafb4fc8047269c
Reviewed-on: https://go-review.googlesource.com/9467
Reviewed-by: Rob Pike <r@golang.org>
GIF's bounds.
Also change the implicit Config Width and Height to be the
Rectangle.Max, not the Dx and Dy, of the first frame's bounds. For the
case where the first frame's bounds is something like (5,5)-(8,8), the
overall width should be 8, not 3.
Change-Id: I3affc484f5e32941a36f15517a92ca8d189d9c22
Reviewed-on: https://go-review.googlesource.com/9465
Reviewed-by: Rob Pike <r@golang.org>
The previous CL implemented decoding, but not encoding.
Also return the global color map (if present) for DecodeConfig.
Change-Id: I3b99c93720246010c9fe0924dc40a67875dfc852
Reviewed-on: https://go-review.googlesource.com/9389
Reviewed-by: Rob Pike <r@golang.org>
call unreadByteStuffedByte.
If ensureNBits was due to an io.EOF that was translated to
jpeg.errShortHuffmanData, then we may have read no bytes, so there is no
byte-stuffed-byte to unread.
Fixes#10387
Change-Id: I39a3842590c6cef2aa48943288d52f603338b44d
Reviewed-on: https://go-review.googlesource.com/8841
Reviewed-by: Rob Pike <r@golang.org>
The background index in the global palette (located in the image.Config)
is necessary for interpreting GIF frames properly
Frame disposal information is necessary for interpreting GIF frames in
the context of a sequence (or animation)
Removes decoder.flags as it can be a local variable
Change-Id: I6790a7febf6ba0859175c834c807bc6413e6b194
Reviewed-on: https://go-review.googlesource.com/4620
Reviewed-by: Nigel Tao <nigeltao@golang.org>
This is in preparation for inlining the color.YCbCrToRGB calls in a
follow-up change.
Change-Id: I30750ace11a8ef6016b3c1e0b4bfdbcc8151f9a5
Reviewed-on: https://go-review.googlesource.com/7951
Reviewed-by: Rob Pike <r@golang.org>
The imageutil.DrawYCbCr function lives in an internal package because it
is needed by both the image/draw and image/jpeg packages, but it doesn't
seem right for one of those two to depend on the other.
It could eventually go into the image package, but that would require
committing to an API for the rest of Go 1.x.
Change-Id: I7b12555c970d86409365e99eef9360702aaffa30
Reviewed-on: https://go-review.googlesource.com/7925
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
components.
This fixes decoding JPEG images where the component selector is 0. Such
images are rare, but not impossible.
Change-Id: I6d221bce01cce8cc0440e117543233371782ca22
Reviewed-on: https://go-review.googlesource.com/6421
Reviewed-by: Rob Pike <r@golang.org>
Grayscale PNG and JPEG images are not uncommon. We should have a fast path.
Also add a benchmark for the recently added CMYK fast path.
benchmark old ns/op new ns/op delta
BenchmarkGray 13960348 324152 -97.68%
Change-Id: I72b5838c8c3d1f2d0a4536a848e020e80b10c0f7
Reviewed-on: https://go-review.googlesource.com/6237
Reviewed-by: Rob Pike <r@golang.org>
