possible bug loss of lzw compression for tiff in convert
Posted: 2014-01-15T21:08:14-07:00
This is a follow up of viewtopic.php?f=3&t=24647#p106920 and the input image is linked there.
The issue is the following. When doing a convert in IM 6.8.7.4 and prior, the LZW compression is carried over to the output. However, starting with IM 6.8.7.5 up to 6.8.8.2, the output has compression none. I do not know if this was intentional or not. I just wanted to verify the user's complaint.
im6874 convert test.tiff test_6874.tiff
compression: LZW
im6875 convert test.tiff test_6876.tiff
compression: none
The input file is an 8/1-bit, grayscale tiff with LZW compression.
The issue is the following. When doing a convert in IM 6.8.7.4 and prior, the LZW compression is carried over to the output. However, starting with IM 6.8.7.5 up to 6.8.8.2, the output has compression none. I do not know if this was intentional or not. I just wanted to verify the user's complaint.
im6874 convert test.tiff test_6874.tiff
compression: LZW
im6875 convert test.tiff test_6876.tiff
compression: none
The input file is an 8/1-bit, grayscale tiff with LZW compression.
Code: Select all
Format: TIFF (Tagged Image File Format)
Mime type: image/tiff
Class: DirectClass
Geometry: 3952x5799+0+0
Units: PixelsPerInch
Type: Bilevel
Base type: Bilevel
Endianess: MSB
Colorspace: Gray
Depth: 8/1-bit
Channel depth:
gray: 1-bit
alpha: 1-bit
Channel statistics:
Gray:
min: 0 (0)
max: 255 (1)
mean: 240.291 (0.942317)
standard deviation: 59.4516 (0.233143)
kurtosis: 12.3973
skewness: -3.79437
Alpha:
min: 255 (1)
max: 255 (1)
mean: 255 (1)
standard deviation: 0 (0)
kurtosis: 0
skewness: 0
Colors: 2
Histogram:
1321964: ( 0, 0, 0,255) #000000 graya(0,1)
21595684: (255,255,255,255) #FFFFFF graya(255,1)
Rendering intent: Undefined
Gamma: 0.454545
Background color: graya(255,1)
Border color: graya(223,1)
Matte color: graya(189,1)
Transparent color: graya(0,0)
Interlace: None
Intensity: Undefined
Compose: Over
Page geometry: 3952x5799+0+0
Dispose: Undefined
Iterations: 0
Compression: LZW
Orientation: TopLeft
Properties:
date:create: 2014-01-15T16:00:50-08:00
date:modify: 2014-01-15T16:00:50-08:00
signature: d13f267488702005c20d0ecf85df08942dcfeb5ac4e88d16efbdb5fcb02665a6
tiff:alpha: unassociated
tiff:endian: msb
tiff:photometric: min-is-black
tiff:rows-per-strip: 16
Artifacts:
filename: test.tiff
verbose: true
Tainted: True
Filesize: 566KB
Number pixels: 22.92M
Pixels per second: 57.29MB
User time: 0.400u
Elapsed time: 0:01.400
Version: ImageMagick 6.8.8-2 Q16 x86_64 2014-01-13 http://www.imagemagick.org