Convert creates multiple files

Shell Programming and Scripting
1

I want to crop an image and am using convert

convert mountain.png -crop 3000x4500 +repage -format png mountain--cr.png

The problem is that convert is creating 4 files

mountain--cr-0.png
mountain--cr-1.png
mountain--cr-2.png
mountain--cr-3.png

The first is what I need, the other look empty

2

Please provide and post full details of your operation system and version of your image utilities.

Thanks.

3

I am using

ImageMagick 6.7.7-10 2014-08-28 Q16

My system is GNU Trisquel 7.0 with Gnome Version 3.8.4

4

Just for fun, have you tried to resize the image before you crop?

Ref:

5

Using the following command did not work, still getting the 4 files.

convert mountain.png -crop 3000x4500 +repage -format png -resize 3000x4500 mountain--cr.png
6

Maybe try resizing first, for fun....

convert mountain.png -resize 3000x4500 mountain-resize.png
convert mountain-resize.png -crop 3000x4500 mountain-resize-crop.png

Or something similar and simple, step-by-step?

Just to see what happens?

7

I have an image with a big canvas, and the image falls within it. I am trying to crop to the size of the actual image.

8

Stupid question: What do you get if you type

identify mountain.png

Maybe the output of that will give a clue as to why you get four files from the convert command.

Andrew

9

OK, but what is the problem? Throw away the other 3 if you don't need them. Or do you want to autmate the process? If so, it would be nice to know your OS, your shell, ... you now the drill. Supposing you can use Korn shell and your system has the standard features how about this:

bakunin@host $ cat myconvert.sh
#! /bin/ksh
typeset fIn="$1"
typeset chExt=".png"
fIn="${fIn#${chExt}}"

if ! [ -f "${fIn}.${chExt}" ; then
     print -u2 "Cannot find file ${fIn}.${chExt}."
     exit 1
fi
if convert "$fIn.$chExt" -crop 3000x4500 +repage -format png "${fIn}--cr.${chExt}" ; then
     rm "${fIn}-cr-1.${chExt}"
     rm "${fIn}-cr-2.${chExt}"
     rm "${fIn}-cr-3.${chExt}"
     mv "${fIn}-cr-0.${chExt}" "${fIn}-cr.${chExt}"
     exit 0
fi

exit $?

I hope this helps.

10

I prefer not to resize the image.

I have a canvas of size 3583 �- 5049 pixels. The image within the png file is 2944x4454.

Just want to crop to 3000x4500, perhaps fill the background with white for the area outside the image

--- Post updated at 03:13 PM ---

I get

mountain.png PNG 3583x5049 3583x5049+0+0 8-bit DirectClass 912KB 0.000u 0:00.000

--- Post updated at 03:18 PM ---

GNU Trisquel 7.0 with Gnome Version 3.8.4running bash

The task is to understand how it is creating the additional files, what are they? Has anybody encountered them before?
I also want to understand if my image is created properly. Are the headers correct, offset etc

--- Post updated at 03:26 PM ---

I now have tried, seem to work. Would this be ok, or do aybody have better suggestions?

convert mountain.png -format png -background white -flatten -crop 3000x4500 +repage mountain--cr.png
11

Well, in this the bash version. You see why it is necessary to state your surroundings?

bakunin@host $ cat myconvert.sh
#! /bin/bash
local fIn="$1"
local chExt=".png"
fIn="${fIn#${chExt}}"

if ! [ -f "${fIn}.${chExt}" ; then
     echo "Cannot find file ${fIn}.${chExt}." >&2
     exit 1
fi
if convert "$fIn.$chExt" -crop 3000x4500 +repage -format png "${fIn}--cr.${chExt}" ; then
     rm "${fIn}-cr-1.${chExt}"
     rm "${fIn}-cr-2.${chExt}"
     rm "${fIn}-cr-3.${chExt}"
     mv "${fIn}-cr-0.${chExt}" "${fIn}-cr.${chExt}"
     exit 0
fi

exit $?

This is a question best asked an expert in picture processing. I have never used this (or any other picture processing) program at all.

I hope this helps.

bakunin