Compile C++ code for iPhone

mcs07 · 05-03-2009, 10:03 AM

I'm attempting to get the Tesseract OCR engine to work with the iPhone.
(tesseract-ocr - Google Code)
Currently what I have done is compile the C++ code through the terminal using the makefile provided with the source code. I then copied the unix executable into my Xcode project, and have written an Objective-C wrapper.

This works great in the simulator, but I'm pretty sure it won't work on the device because the tesseract C++ is compiled for the Mac, not for ARM/iPhone.

Searching for a solution I came across this blog post:
Latenitesoft: Mac & iPhone Applications: iPhone Programming Tips: building Unix software

The section explaining "The Problem" sounds identical to my problem, but unfortunately I don't really understand "The Solution" section at all.

So I was wondering if anyone else had tried something like this and got it to work, or if anyone knows of a tutorial or explanation of what to do.

jolly1312 · 05-12-2009, 05:21 PM

I am trying to do something very similar to what you are doing. I usually cross compile for ARM on Linux and Unix systems but I am totally unaware of ObjectiveC and iphone SDK.

I'll try to cross compile tesseract OCR over the weekend and provide you the shell commands to get it done for your system.

If possible, can you provide me to the sample xcode project with simple objective-C wrapper to test my compilation?

jsonli · 05-12-2009, 08:25 PM

Neat stuff. Let us know how this goes... interested in dabbling in this too.

larlid · 06-24-2009, 02:00 PM

If you managed to compile it, then I'm interested in the files. I've worked with tesseract before and it's very good if you train it for something specific. I'm currently using it for number recogniction in a project with about 99% accuracy. I would love to use the a port to a similar project to the Iphone.
Thanks, Lars.

zim · 07-01-2009, 10:54 PM

What the blog post is suggesting is that you compile the library from the command line (which you have said you can do :-) for both the iPhone (architecture arm-apple-darwin9) and the iPhone Simulator (architecture i386) as a fat static library (that is, a library that gets built into your executable statically at compile time, rather than loaded in dynamically at run time, where the library contains code for both architectures) and add the library and header files to your project.

This avoids the need for you to define the rules necessary to build the libraries from within Xcode.

Code:

export DEVROOT=/Developer/Platforms/iPhoneOS.platform/Developer
export SDKROOT=$DEVROOT/SDKs/iPhoneOS3.0.sdk
export CPPFLAGS="-I$SDKROOT/usr/lib/gcc/arm-apple-darwin9/4.0.1/include/ -I$SDKROOT/usr/include/"
export CFLAGS="$CPPFLAGS -arch armv6 -pipe -no-cpp-precomp -isysroot $SDKROOT"
export CPP="$DEVROOT/usr/bin/cpp $CPPFLAGS"
export LDFLAGS="-L$SDKROOT/usr/lib/ -Wl,-dylib_install_name,@executable_path/$LIBNAME"
export CXXFLAGS="$CFLAGS"
./configure CXX=/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/arm-apple-darwin9-g++-4.0.1 CC=$DEVROOT/usr/bin/arm-apple-darwin9-gcc-4.0.1 LD=$DEVROOT/usr/bin/ld --host=arm-apple-darwin
make
cp ccmain/libtesseract_full.a libtesseract_full_armv6.a
make distclean
unset CPPFLAGS CFLAGS CPP LDFLAGS CPP CXXFLAGS
./configure
make
cp ccmain/libtesseract_full.a libtesseract_full_i386.a
$DEVROOT/usr/bin/lipo -arch armv6 libtesseract_full_armv6.a -arch i386 libtesseract_full_i386.a -create -output libtesseract_full.a

Add that libtesseract_full.a file to your Xcode project's Frameworks section, set an include path entry in project settings or add the relevant include files into your project, and you should be set.

init5 · 07-07-2009, 03:06 PM

Hi,
is there any sample implemetation to test the lib?

BR
init5

fracasado · 07-14-2009, 07:24 PM

zim, I'm doing what you said but when I execute the last step, I get this error:

command to execute:

$DEVROOT/usr/bin/lipo -arch armv6 libtesseract_full_armv6.a -arch i386 libtesseract_full_i386.a -create -output libtesseract_full.a

and the Error:

/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/lipo: specifed architecture type (armv6) for file (libtesseract_full_armv6.a) does not match it's cputype (7) and cpusubtype (3) (should be cputype (12) and cpusubtype (6))

Could you help me, please, because I don't know how to solve this problem
Thanks

mcs07 · 07-29-2009, 03:30 PM

This blog post was pretty useful:
exploration Blog Archive cross-compiling for iPhone dev

olipion · 08-21-2009, 04:46 PM

Quote:

Originally Posted by mcs07

This blog post was pretty useful:
exploration Blog Archive cross-compiling for iPhone dev

You can check my cross compilation tutorial on iphone.olipion.com
I show how to cross-compile library such libssh2, libcurl, zbar barcode reader or tesseract ocr for iphone and simulator.

Regards,
Olipion

larlid · 09-03-2009, 01:17 PM

I've managed to compile it now, but I get an linking error when I try to:
static int result = tess->InitWithLanguage(NULL,NULL,NULL,NULL,false,0,NULL );

This works fine though:
TessBaseAPI *tess = new TessBaseAPI();

The error is symbol not found...

Anybody who has managed to use tesseract in any way yet?
Lars.

Gregoire · 10-13-2009, 05:01 PM

Quote:

Originally Posted by larlid

I've managed to compile it now, but I get an linking error when I try to:
static int result = tess->InitWithLanguage(NULL,NULL,NULL,NULL,false,0,NULL );

This works fine though:
TessBaseAPI *tess = new TessBaseAPI();

The error is symbol not found...

Anybody who has managed to use tesseract in any way yet?
Lars.

Hi,

After reading your posts I was wondering if you made it work or not

cheers

greg

therock · 11-02-2009, 01:59 AM

Can you help me with entire xcode proj file as i am stuck with code39 bar code reader for IPhone , if you help me with the xcode project file i will be great

therock · 11-02-2009, 02:00 AM

would you like to help with xcode project file , that will help a lot

subhasis_bose · 12-21-2009, 02:54 AM

Hi

I am able to run the tesseract -ocr library in a IPhone simulator and it seems to work nice and fine.

But when I tried to build the code for Iphone device I got the following error:

'libtesseract_full.a, file is not of required architecture'

I am using MAC OSX10.5.8 and Iphone SDK3.1.

It will be very nice if somebody can help me on this issue.
Desperately looking for a solution to this.

Lots of thanks in advance...

Thanks & Regards
Subhasis

elninom · 02-21-2010, 07:03 AM

I can compile Tesseract 2.04 but this script does not work for Tesseract 3.0 svn. Has anyone can success for compiling latest version?

geniass · 06-04-2010, 08:21 AM

Hi I was wondering if this library that works on the iPhone would work on a different phone (Samsung Wave) which has a very similar processor. If not can someone please find a way to do this? I have no idea how and I dont have a Mac or Linux xomputer. Please reply quickly I need help soon>

sam1122 · 09-10-2010, 01:24 AM

HI,
I'm using the following script to build the tesseract in my mac OS X 10.6.2. I'm getting the following error, please help me to resolve this.

Regards,
Shane.

=========Script============
#!/bin/sh

# build_fat.sh
#
# Created by Robert Carlsen on 15.07.2009.
# Updated 6.12.2009 to build i386 (simulator) on an x86_64 platform (10.6 SDK)
# build an arm / i386 lib of standard linux project
#
# adopted from:
# Latenitesoft: Mac & iOS Applications: iPhone Programming Tips: building Unix software
#
# initially configured for tesseract-ocr

# Set up the target lib file / path
# easiest to just build the package normally first and watch where the files are created.
LIBFILE=ccmain/libtesseract_full

# Select the desired iPhone SDK
export DEVROOT=/Developer/Platforms/iPhoneOS.platform/Developer
export SDKROOT=$DEVROOT/SDKs/iPhoneOS4.0.sdk
export PATH=$DEVROOT/usr/bin:$PATH

# Set up relevant environment variables
export CPPFLAGS="-I$SDKROOT/usr/lib/gcc/arm-apple-darwin10/4.0.1/include/ -I$SDKROOT/usr/include/ -miphoneos-version-min=4.0"
export CFLAGS="$CPPFLAGS -arch armv6 -pipe -no-cpp-precomp -isysroot
$SDKROOT"
export CPP="$DEVROOT/usr/bin/cpp $CPPFLAGS"
export CXXFLAGS="$CFLAGS"

# Dynamic library location generated by the Unix package
LIBPATH=$LIBFILE.dylib
LIBNAME=`basename $LIBPATH`

export LDFLAGS="-L$SDKROOT/usr/lib/ -Wl,-
dylib_install_name,@executable_path/$LIBNAME"

# Static library that will be generated for ARM
LIBPATH_static=$LIBFILE.a
LIBNAME_static=`basename $LIBPATH_static`

# TODO: add custom flags as necessary for package
./configure CXX=$DEVROOT/usr/bin/arm-apple-darwin10-g++-4.0.1 CC=$DEVROOT/usr/bin/arm-apple-darwin10-gcc-4.0.1 LD=$DEVROOT/usr/bin/ld --
host=arm-apple-darwin

make -j4

# Copy the ARM library to a temporary location
mkdir -p lnsout
cp $LIBPATH_static lnsout/$LIBNAME_static.arm

# Do it all again for native cpu
make distclean

# Restore default environment variables
unset CPPFLAGS CFLAGS CPP LDFLAGS CXXFLAGS DEVROOT SDKROOT

export DEVROOT=/Developer
export SDKROOT=$DEVROOT/SDKs/MacOSX10.6.sdk

export CPPFLAGS="-I$SDKROOT/usr/lib/gcc/i686-apple-darwin10/4.0.1/include/ -I$SDKROOT/usr/include/ -mmacosx-version-min=10.5"
export CFLAGS="$CPPFLAGS -pipe -no-cpp-precomp -isysroot $SDKROOT -arch i386"
export CPP="$DEVROOT/usr/bin/cpp $CPPFLAGS"
export CXXFLAGS="$CFLAGS"

#Overwrite LDFLAGS
# Dynamic linking, relative to executable_path
# Use otool -D to check the install name
export LDFLAGS="-Wl,-dylib_install_name,@executable_path/$LIBNAME"

# TODO: error checking
./configure
make -j4

# Copy the native library to the temporary location
cp $LIBPATH_static lnsout/$LIBNAME_static.i386

# Create fat lib by combining the two versions
/usr/bin/lipo -arch arm lnsout/$LIBNAME_static.arm -arch i386 lnsout/$LIBNAME_static.i386 -create -output lnsout/$LIBNAME_static

unset CPPFLAGS CFLAGS CPP LDFLAGS CPP CXXFLAGS DEVROOT SDKROOT
==========================

===Error i'm Getting============
/usr/bin/lipo: specifed architecture type (arm) for file (lnsout/libtesseract_full.a.arm) does not match it's cputype (16777223) and cpusubtype (3) (should be cputype (12) and cpusubtype (0))
=======

Cheers,

jaxian · 09-22-2010, 02:20 PM

Quote:

Originally Posted by olipion

You can check my cross compilation tutorial on iphone.olipion.com
I show how to cross-compile library such libssh2, libcurl, zbar barcode reader or tesseract ocr for iphone and simulator.

Regards,
Olipion

any idea on how to implement libssh2 connection, authentication via password and executing command uptime only when a button is pressed (command execudted only when the button is pressed)? Please help!