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LibGfx/TIFF: Add support for images with CCITT3 1D compression

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This compression (tag Compression=2) is not very popular on its own, but
a base to implement CCITT3 2D and CCITT4 compressions.

As the format has no real benefits, it is quite hard to find an app that
accepts tho encode that for you. So I used the following program that
calls `libtiff` directly:
```cpp
#include <vector>
#include <cstdlib>
#include <iostream>

#include <tiffio.h>

// An array containing 0 and 1 of length width * height.
extern std::vector<uint8_t> array;
int main() {
    // From: https://stackoverflow.com/a/34257789

    TIFF *image = TIFFOpen("input.tif", "w");
    int const width = 400;
    int const height = 300;
    TIFFSetField(image, TIFFTAG_IMAGEWIDTH, width);
    TIFFSetField(image, TIFFTAG_IMAGELENGTH, height);
    TIFFSetField(image, TIFFTAG_PHOTOMETRIC, 0);
    TIFFSetField(image, TIFFTAG_COMPRESSION, COMPRESSION_CCITTRLE);

    TIFFSetField(image, TIFFTAG_BITSPERSAMPLE, 1);
    TIFFSetField(image, TIFFTAG_SAMPLESPERPIXEL, 1);
    TIFFSetField(image, TIFFTAG_ROWSPERSTRIP, 1);

    std::vector<uint8_t> scan_line(width / 8 + 8, 0);
    int count = 0;
    for (int i = 0; i < height; i++) {
        std::fill(scan_line.begin(), scan_line.end(), 0);
        for (int x = 0; x < width; ++x) {
            uint8_t eight_pixels = scan_line.at(x / 8);
            eight_pixels = eight_pixels << 1;
            eight_pixels |= !array.at(i * width + x);
            scan_line.at(x / 8) = eight_pixels;
        }
        int bytes = int(width / 8.0 + 0.5);
        if (TIFFWriteScanline(image, scan_line.data(), i, bytes) != 1)
            std::cerr << "Something went wrong\n";
    }

    TIFFClose(image);
}
```
This commit is contained in:
Lucas CHOLLET 2023-11-25 16:34:56 -05:00 • committed by Andreas Kling
parent 7266d8c35d
commit 64912d4d02
6 changed files with 388 additions and 1 deletions
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12
Tests/LibGfx/TestImageDecoder.cpp
View file

@ -406,6 +406,18 @@ TEST_CASE(test_tiff_uncompressed)
EXPECT_EQ(frame.image->get_pixel(60, 75), Gfx::Color::NamedColor::Red);
}
TEST_CASE(test_tiff_ccitt3_1d)
{
auto file = MUST(Core::MappedFile::map(TEST_INPUT("tiff/ccitt3_1d.tiff"sv)));
EXPECT(Gfx::TIFFImageDecoderPlugin::sniff(file->bytes()));
auto plugin_decoder = TRY_OR_FAIL(Gfx::TIFFImageDecoderPlugin::create(file->bytes()));
auto frame = TRY_OR_FAIL(expect_single_frame_of_size(*plugin_decoder, { 400, 300 }));
EXPECT_EQ(frame.image->get_pixel(0, 0), Gfx::Color::NamedColor::White);
EXPECT_EQ(frame.image->get_pixel(60, 75), Gfx::Color::NamedColor::Black);
}
TEST_CASE(test_tiff_lzw)
{
auto file = MUST(Core::MappedFile::map(TEST_INPUT("tiff/lzw.tiff"sv)));