Search found 151 matches

by 246246
2018-04-24T05:09:02-07:00
Forum: Users
Topic: Compress BMP with RLE
Replies: 9
Views: 235

Re: Compress BMP with RLE

qwermike wrote:
2018-04-23T23:27:30-07:00
I need it just to compare times for different compression algorithms.
Then, I think tiff is proper format. It support RLE, LZW, Zip, Jpeg compression with libtiff.
by 246246
2018-04-24T03:17:31-07:00
Forum: Users
Topic: Invalid TIFF directory; tags are not sorted in ascending order. `TIFFReadDirectoryCheckOrder'
Replies: 11
Views: 381

Re: Invalid TIFF directory; tags are not sorted in ascending order. `TIFFReadDirectoryCheckOrder'

Is 2046 and 477825 is common for all the files ? If not How do i get to know which bytes needs to remove. See StripOffsets (273) LONG (4) 1<2046> StripByteCounts (279) LONG (4) 1<477825> from command output above. If all your files are created by same software, there is a chance to be able to extra...
by 246246
2018-04-23T17:03:10-07:00
Forum: Users
Topic: Compress BMP with RLE
Replies: 9
Views: 235

Re: Compress BMP with RLE

I have not found such program yet, or even have not found RLE24 compressed bitmap sample file. Some products may read/write such files, for example https://www.leadtools.com/help/leadtools/v19/dh/to/l-topics-fileformatsbmpformats.html, but i'm not tried it yet. I guess most software ignore RLE compr...
by 246246
2018-04-23T07:34:43-07:00
Forum: Users
Topic: Invalid TIFF directory; tags are not sorted in ascending order. `TIFFReadDirectoryCheckOrder'
Replies: 11
Views: 381

Re: Invalid TIFF directory; tags are not sorted in ascending order. `TIFFReadDirectoryCheckOrder'

According to tiffdump, $ tiffdump NotWorking.tiff NotWorking.tiff: Magic: 0x4949 <little-endian> Version: 0x2a <ClassicTIFF> Directory 0: offset 8 (0x8) next 0 (0) SubFileType (254) LONG (4) 1<0> ImageWidth (256) LONG (4) 1<1700> ImageLength (257) LONG (4) 1<2200> BitsPerSample (258) SHORT (3) 1<8> ...
by 246246
2018-04-23T06:08:39-07:00
Forum: Users
Topic: Compress BMP with RLE
Replies: 9
Views: 235

Re: Compress BMP with RLE

But seems like user 246246 found what I'm doing wrong. Now I'm curious can ImageMagick convert my bmp to OS/2 format? P.S. I tried to compress OS/2 24bit image, but no effect. And identify shows that it is BMP2. I think you tried to read OS/2 BMP v1, which is practically identical to Windows bitmap...
by 246246
2018-04-22T17:29:35-07:00
Forum: Users
Topic: Compress BMP with RLE
Replies: 9
Views: 235

Re: Compress BMP with RLE

As far as I know RLE compression for bmp is only applicable for 4-bit or 8-bit bitmap (unless it is OS/2 format). https://msdn.microsoft.com/en-us/library/windows/desktop/dd183383(v=vs.85).aspx https://en.wikipedia.org/wiki/BMP_file_format#Compression From file size, your matterhorn.bmp is 24-bit RG...
by 246246
2018-04-13T20:54:24-07:00
Forum: Users
Topic: Why %[bit-depth] is sometimes 8 and sometimes 16 for indexed tiff?
Replies: 11
Views: 2168

Re: Why %[bit-depth] is sometimes 8 and sometimes 16 for indexed tiff?

fmw42 wrote:
2018-03-22T08:58:27-07:00
I do not see any %[bit-depth] listed at https://www.imagemagick.org/script/escape.php. Where is that documented?
I found it is mentioned here:
viewtopic.php?t=24291
by 246246
2018-04-13T19:23:48-07:00
Forum: Users
Topic: Saving image as a palette type bmp, even if it is greyscale?
Replies: 4
Views: 283

Re: Saving image as a palette type bmp, even if it is greyscale?

boot-backup.bmp is a 24-bits/pixel uncompressed RGB file, which (I guess) ImageMagick pretends is paletted, since it only has 16 colors. Note the class is "DirectClass", which means non-paletted. Note the file size is 230KB, which is about 3 bytes/pixel. Indeed. Also, 'identify -verbose boot-backup...
by 246246
2018-04-12T06:38:05-07:00
Forum: Users
Topic: Saving image as a palette type bmp, even if it is greyscale?
Replies: 4
Views: 283

Re: Saving image as a palette type bmp, even if it is greyscale?

I think your boot.bmp is palette format because identify -verbose shows colormap entry. Create file just the same way you've done: % convert logo: -type Palette -colorspace Gray PNG8:logo.png % convert logo.png -type Palette BMP3:logo.bmp Then checking it. % identify -verbose logo.bmp | grep -A 10 -...
by 246246
2018-03-22T19:55:12-07:00
Forum: Users
Topic: Why %[bit-depth] is sometimes 8 and sometimes 16 for indexed tiff?
Replies: 11
Views: 2168

Re: Why %[bit-depth] is sometimes 8 and sometimes 16 for indexed tiff?

Thank you for your clear explaiation, snibgo! I neverimagined such simple calculation exists --- well, 255 * 257 = 65535.
by 246246
2018-03-22T17:30:20-07:00
Forum: Users
Topic: IM can't handle %% in paths
Replies: 15
Views: 2389

Re: IM can't handle %% in paths

snibgo wrote:
2018-03-22T16:15:20-07:00
The difficulty is that IM treats some characters in output filenames as special. For example "output_%[filename:mysize].tif" will substitute %[...] with something else.
Thank you for remembering this. I had thought the result in my simple testcase is an obvious bug. :)
by 246246
2018-03-22T17:15:28-07:00
Forum: Users
Topic: Why %[bit-depth] is sometimes 8 and sometimes 16 for indexed tiff?
Replies: 11
Views: 2168

Re: Why %[bit-depth] is sometimes 8 and sometimes 16 for indexed tiff?

@246246: Did you follow the trail? property.c "bit-depth" calls attribute.c GetImageDepth() which reads the entire image to find the number of bits required. I'm now trying to :) Your command for logo2.tif finds the best two colours that fit the image. You use Q16, and those colours are likely to n...
by 246246
2018-03-22T17:02:55-07:00
Forum: Users
Topic: Why %[bit-depth] is sometimes 8 and sometimes 16 for indexed tiff?
Replies: 11
Views: 2168

Re: Why %[bit-depth] is sometimes 8 and sometimes 16 for indexed tiff?

fmw42 wrote:
2018-03-22T16:19:20-07:00
Is it not the other way around, as

16/1-bit
Sorry I don't understand what you mean:

$ magick identify -verbose logo1.tif | grep Depth
Depth: 1/8-bit
$ magick identify -verbose logo2.tif | grep Depth
Depth: 1/16-bit
by 246246
2018-03-22T15:57:20-07:00
Forum: Users
Topic: Why %[bit-depth] is sometimes 8 and sometimes 16 for indexed tiff?
Replies: 11
Views: 2168

Re: Why %[bit-depth] is sometimes 8 and sometimes 16 for indexed tiff?

I read it about this forum some years ago, but I cannot find the post. (I'll add it later if I could find it.) I'm sure that property is implemented. https://github.com/ImageMagick/ImageMagick/search?l=C&q=bit-depth&type=&utf8=%E2%9C%93 It seems same value are shown in the output of identify -verbos...
by 246246
2018-03-22T07:04:36-07:00
Forum: Users
Topic: IM can't handle %% in paths
Replies: 15
Views: 2389

Re: IM can't handle %% in paths

akes wrote:
2018-03-22T06:29:02-07:00
And since some of the images are 300MB+ I do not want to copy them before running the IM command.
As you are in linux, you can use mv instead of cp if the partition is same.
Probably better way is to use symbolic link.