Remove freeimage dependency

[solonovamax]

Freeimage has several different vulnerabilities in it and the library is no longer maintained and has not been updated since 2018.
Because of this, it has been dropped from many different distributions, such as nixpkgs: NixOS/nixpkgs#454867

This makes building gazebo on those distributions more difficult.
It does not seem that freeimage is used that extensively within gazebo, it is basically only present in a single place:

gz-rendering/optix/src/OptixTextureFactory.cc

Lines 54 to 110 in a395a95

	optix::Buffer OptixTextureFactory::CreateBuffer(const std::string &_filename)
	{
	if (_filename.empty())
	{
	gzerr << "Cannot load texture from empty filename" << std::endl;
	return this->CreateBuffer();
	}
	FREE_IMAGE_FORMAT format = FreeImage_GetFileType(_filename.c_str(), 0);
	FIBITMAP *image = FreeImage_Load(format, _filename.c_str());
	if (!image)
	{
	gzerr << "Unable to load texture: " << _filename << std::endl;
	return this->CreateBuffer();
	}
	FIBITMAP *temp = image;
	image = FreeImage_ConvertTo32Bits(image);
	unsigned w = FreeImage_GetWidth(image);
	unsigned h = FreeImage_GetHeight(image);
	// freeimage stores data as BGR[A] on little endian architecture
	// reverse pixel values if needed
	#if FREEIMAGE_COLORORDER == FREEIMAGE_COLORORDER_BGR
	unsigned p = FreeImage_GetPitch(image);
	unsigned bpp = FreeImage_GetBPP(image) / 8;
	unsigned lineSize = FreeImage_GetLine(image);
	BYTE* line = FreeImage_GetBits(image);
	for (unsigned y = 0; y < h; ++y, line += p)
	{
	for (BYTE* pixel = line; pixel < line + lineSize; pixel += bpp)
	{
	// in- place swap
	pixel[0] ^= pixel[2]; pixel[2] ^= pixel[0]; pixel[0] ^= pixel[2];
	}
	}
	#endif
	FreeImage_Unload(temp);
	optix::Context optixContext = this->scene->OptixContext();
	optix::Buffer buffer = optixContext->createBuffer(RT_BUFFER_INPUT);
	buffer->setFormat(RT_FORMAT_UNSIGNED_BYTE4);
	buffer->setSize(w, h);
	// get raw bits after flipping vertical axis (last bool arg)
	// as free image stores data upside down in memory
	FreeImage_ConvertToRawBits(reinterpret_cast<BYTE *>(buffer->map()),
	image, FreeImage_GetLine(image), FreeImage_GetBPP(image),
	FI_RGBA_RED_MASK, FI_RGBA_GREEN_MASK, FI_RGBA_BLUE_MASK, true);
	buffer->unmap();
	FreeImage_Unload(image);
	return buffer;
	}

so it should be relatively straightforward to replace freeimage which supports a bunch of other image formats.

Here is a list of all of the known unfixed vulnerabilities in freeimage:

• CVE-2019-12212
• CVE-2019-12214
• CVE-2020-21426
• CVE-2020-21427
• CVE-2020-21428
• CVE-2020-22524
• CVE-2020-24292
• CVE-2020-24293
• CVE-2020-24294
• CVE-2020-24295
• CVE-2021-33367
• CVE-2021-40262
• CVE-2021-40263
• CVE-2021-40264
• CVE-2021-40265
• CVE-2021-40266
• CVE-2023-47992
• CVE-2023-47993
• CVE-2023-47994
• CVE-2023-47995
• CVE-2023-47996
• CVE-2023-47997
• CVE-2024-28562
• CVE-2024-28563
• CVE-2024-28564
• CVE-2024-28565
• CVE-2024-28566
• CVE-2024-28567
• CVE-2024-28568
• CVE-2024-28569
• CVE-2024-28570
• CVE-2024-28571
• CVE-2024-28572
• CVE-2024-28573
• CVE-2024-28574
• CVE-2024-28575
• CVE-2024-28576
• CVE-2024-28577
• CVE-2024-28578
• CVE-2024-28579
• CVE-2024-28580
• CVE-2024-28581
• CVE-2024-28582
• CVE-2024-28583
• CVE-2024-28584
• CVE-2024-31570
• CVE-2024-9029
• CVE-2025-65803
• CVE-2025-70968

in order to replace freeimage, you'd want to find some other library that supports a bunch of similar formats to the ones freeimage supports.

freeimage supports the following file formats:

• bmp
• ico
• jpeg
• jng
• koala
• lbm/iff
• mng
• pbm/pbmraw
• pcd
• pcx
• pgm/pgmraw
• png
• ppm/ppmraw
• ras
• targa
• tiff
• wbmp
• psd
• cut
• xbm
• xpm
• dds
• gif
• hdr
• faxg3
• sgi
• exr
• j2k
• jp2
• pfm
• pict
• raw
• webp
• jxf

one option would be to use opencv, which supports the following file formats:

• bmp
• ico
• jpeg
• jng
• koala
• lbm/iff
• mng
• pbm/pbmraw
• pcd
• pcx
• pgm/pgmraw
• png
• ppm/ppmraw
• ras
• targa
• tiff
• wbmp
• psd
• cut
• xbm
• xpm
• dds
• gif
• hdr
• faxg3
• sgi
• exr
• j2k
• jp2
• pfm
• pict
• raw
• webp
• jxf

as well as several niche formats that are not supported by freeimage.

out of the formats which are not supported by opencv, they seem to be extremely niche, and are likely very seldom used.

alternatively, another library which supports all those formats could be found.

related: gazebosim/gz-common#388 (didn't see this issue until afterwards, oopsies)

[iche033]

Related PR to replace FreeImage in gz-common: gazebosim/gz-common#725

All optix code was also removed in the main branch: #1204. So there won't be any FreeImage code in gz-rendering going forward.

[solonovamax]

All optix code was also removed in the main branch: #1204. So there won't be any FreeImage code in gz-rendering going forward.

ideally a removal of freeimage could be backported, as I'm still using ros jazzy but with nix, so I have to deal with nix's removal of freeimage

[iche033]

for gz-rendering specifically, we're actually not building / releasing the package with optix plugin (that has FreeImage code) on ubuntu, mac (homebrew), or windows (conda). Fox NixOS, I suggest building gz-rendering without optix support (it's optional and disabled by default). If gazebosim/gz-common#725 can be backported, then we can completely get rid of FreeImage in our stable releases.

[scpeters]

while gz-common and gz-rendering no longer directly use freeimage, ogre is still using it, so I think we should think about building new ogre debs with the following patch:

• STBI image codec fixes OGRECave/ogre-next#562

see also the following packaging work:

• https://github.com/lopsided98/nix-ros-overlay/pull/746/changes#diff-f313a59344b40e823f52976785b52930c241448af5626de4e2610972f9dfc0afR174-R204