Issue with dealing TIFF files, contains channels and transparency

[Carter J]

The same command works for both images:

Code: Select all

convert MultiChannelTiffFile.tif -backgound white -flatten x2.jpg

Hi,

This command not worked for below file

https://www.dropbox.com/s/7t2qkk9yzaops ... e.tif?dl=0

Actual image lost and we are able to view only background of that image.

IM version: 6.9.0-6 Q16 x64 (windows) and 6.8.8-7 Q16 x86_64 (Linux)

Any insight?

[Carter J]

Hi,

Could anyone suggest how to proceed with these kind of images...

[snibgo]

"-flatten" isn't needed here.

Code: Select all

convert MultiChannelTiffFile.tif x2.jpg

[Carter J]

"-flatten" isn't needed here.

Code: Select all

convert MultiChannelTiffFile.tif x2.jpg

Thanks for looking into it..

Above command is working, but when we are trying to change resolution or applying "-layers merge" the same is not working...We are using below command to change resolution..

Code: Select all

convert MultiChannelTiffFile.tif -units pixelsperinch -resample 72 output.jpg

[/b]

or to merge layers

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convert -layers merge MultiChannelTiffFile.tif  output.jpg

Any insight?

[snibgo]

So, for this image, "-alpha off" does what you probably want:

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convert MultiChannelTiffFile.tif -alpha off -units pixelsperinch -resample 72 output.jpg

[Carter J]

So, for this image, "-alpha off" does what you probably want:

Code: Select all

convert MultiChannelTiffFile.tif -alpha off -units pixelsperinch -resample 72 output.jpg

Thank you...

Exactly we are facing problem here..

We are using generic command to deal with all types of TIFF, so to deal with above file we have included "alpha off" in the command.

But, for other tiffs we are losing transparency (after including "alpha off")..

Sample input file (for which we are losing transparency):

https://www.dropbox.com/s/1gh3xf99ohlco ... e.tif?dl=0

We want to know how to detect for which images we need to include "alpha off" ?

Any insight?

[Carter J]

Hi,
Could anyone suggest, how to resolve above issue?

[fmw42]

IM may deal with background transparency and alpha channel transparency differently. You check each in Photoshop to see which is giving you trouble. Then use EXIFTOOL to check the image before IM processing to know which kind of transparency you have in that image. This is just a guess. The IM developers may need to look further into TIFF processing with various transparency.

[Carter J]

Hi,

Thanks for suggestion.

We will check and update you

[Carter J]

IM may deal with background transparency and alpha channel transparency differently. You check each in Photoshop to see which is giving you trouble. Then use EXIFTOOL to check the image before IM processing to know which kind of transparency you have in that image. This is just a guess. The IM developers may need to look further into TIFF processing with various transparency.

Hi,

We couldn't able to figure out type of transparency using EXIFTOOL?

We have posted in IM fourms for guidance, but couldn't get any useful info. below is the reference link:

http://u88.n24.queensu.ca/exiftool/foru ... 435.0.html

Do we have any other way to determine transparencies?


Thanks,

[fmw42]

see

0x0152 ExtraSamples N -
0 = Unspecified
1 = Associated Alpha
2 = Unassociated Alpha

at http://www.sno.phy.queensu.ca/~phil/exi ... /EXIF.html