Image to CAD

A program that converts images to CAD readable files.

Executables:

• Image to CAD - A program that converts a given black and white image to a CAD 3d representation of the image (using Irit format .itd).
• Image to CAD preprocess - A program that only run the preprocessing part of the Image to CAD program.

Produced files:

• preprocessed.png - The result of the preprocessing step.
• surfaces.itd - The generated surfaces (2d) in Irit format.
• extrusions.itd - The generated extruded surfaces (3d) in Irit format.
• Other files - Files used to debug the program (usually have a self explanatory name).

Prerequisites

• Windows (Currently tested only on this os may work on other os like linux as well)
• cmake (version >= 3.17)
• Compiler which support cpp17 (Currently tested on msvc143 as provided by vs2022)
• Irit library (Compiled using a matching compiler to the one used to compile this project), set IRIT_ROOT/IRIT64_ROOT environment variable to the irit bin directory (where the irit.dll/irit64.dll/irit.a/irit.so is located, usually under ntbin/ntbin64/bin directory). Match the bitness (32/64) of the compiler used to compile this project

Soft prerequisites

• Boost (version == 1.80.0), set BOOST_ROOT environment variable to the boost root directory to use a local boost installation.
• OpenCV (version == 4.6.0), set OpenCV_DIR environment variable to the opencv root directory to use a local opencv installation.

The soft prerequisites will be downloaded and compiled automatically if not found.

Compiling the program

clone the repo:

git clone --depth 1 --recurse-submodules --shallow-submodules https://github.com/NadavT/image_to_cad_cpp.git image_to_cad
cd image_to_cad

We use --depth 1 to only clone the latest commit and --recurse-submodules to clone all submodules.

build

Make sure to have the prerequisites installed and set the environment variables if needed.

Windows

Open a supported build shell (x64 Native Tools Command Prompt/Developer Command Prompt for VS.../Developer Powershell for VS... or any other shell which has cmake and supported compiler and generator in the path) and run:
(A shell which has cmake and supported compiler and generator in the path)

using nmake - provided by MSVC by default:

mkdir install
mkdir build && cd build
cmake -DCMAKE_INSTALL_PREFIX="../install" -DCMAKE_BUILD_TYPE=Release -G "NMake Makefiles" ..
cmake --build . --target image_to_cad image_to_cad_preprocess -j 6
cmake --install . --component image_to_cad
cmake --install . --component image_to_cad_preprocess

using ninja - preferred if installed (support parallel compilation):

mkdir install
mkdir build && cd build
cmake -DCMAKE_INSTALL_PREFIX="../install" -DCMAKE_BUILD_TYPE=Release -G "Ninja" ..
cmake --build . --target image_to_cad image_to_cad_preprocess -j 6
cmake --install . --component image_to_cad
cmake --install . --component image_to_cad_preprocess

Linux

Open any shell with cmake, supported compiler and generator in the path, and run:

mkdir install
mkdir build && cd build
cmake -DCMAKE_INSTALL_PREFIX="../install" -DCMAKE_BUILD_TYPE=Release ..
cmake --build . --target image_to_cad image_to_cad_preprocess -j 6
cmake --install . --component image_to_cad
cmake --install . --component image_to_cad_preprocess

Running the program

Run image_to_cad.exe from install dir.

Arguments

Run image_to_cad.exe --help to see the latest arguments and their description.

Try default arguments first and tweak them if needed, usually --border is needed to inputs with no black border at the edges of the image.
If using full executable (not preprocess only) with a preprocessed image, use --no_preprocessing flag, make sure to match the --border flag when using --no_preprocessing with the preprocessing run which generated the preprocessed image.

General arguments

flags	description
-h –help	shows help message and exits [default: false]
-v –version	prints version information and exits [default: false]
-i –input	Input image [required]
-o –output_dir	Output directory [default: “results”]

Preprocessing arguments

flags	description
-no_pp –no_preprocessing	Should not apply preprocessing to input image [default: false]
-no_cbw –no_convert_to_black_and_white	Should not convert to black and white [default: false]
-no_cft –no_crop_to_fit	Should not crop to fit [default: false]
-ctf_pl –crop_to_fit_padding_left	Crop to fit padding left [default: 0]
-ctf_pr –crop_to_fit_padding_right	Crop to fit padding right [default: 0]
-ctf_pt –crop_to_fit_padding_top	Crop to fit padding top [default: 0]
-ctf_pb –crop_to_fit_padding_bottom	Crop to fit padding bottom [default: 0]
-it –islands_threshold	Islands threshold [default: 25]
-s –scale	Scale factor [default: 4]
-b –border	Should add border [default: false]

Graph processing arguments

flags	description
-r –reduction_proximity	Reduction proximity [default: 10]
-lt –hanging_leaf_threshold	Hanging leaf threshold [default: 250]
-jct –junction_collapse_threshold	Junction collapse threshold [default: 20]
-jst –junction_smooth_threshold	Junction smooth threshold [default: 10]

Surface generation arguments

flags	description
-co –curve_order	Assign the maximal order of the curve (B-Spline), use -1 to unlimited (Bezier curve) [default: 100]
-tco –target_curve_order	Assign the target order of the curve (B-Spline), use -1 to unlimited (Bezier curve) [default: 4]
-cd –curve_density	density of the curves (number of points per unit length of arc) [default: 0.1]
-cml –curve_min_length	minimum control points of the curves [default: 3]
-jra –junction_radius_adder	The radius of the junctions will be increased by this value (for treaming the outgoing curves [default: 6]
-ex –extrusion	Extrusion amount [default: 25]

Filter offset curves arguments (usually not needed)

flags	description
-foc –filter_offset_curves	Should filter offset curves [default: false]
-dbs –distance_to_boundary_samples	distance to boundary samples [default: 5]
-dbt –distance_to_boundary_threshold	distance to boundary threshold [default: 2]
-dbb –distance_in_boundary_backoff	distance in boundary backoff [default: 0.1]
-dbf –distance_in_boundary_factor	distance in boundary factor [default: 10]

Extras

Resources

Find resources and images to use as input here.