--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/jbig2dec/jbig2_image_pbm.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,162 @@
+/* Copyright (C) 2001-2023 Artifex Software, Inc.
+   All Rights Reserved.
+
+   This software is provided AS-IS with no warranty, either express or
+   implied.
+
+   This software is distributed under license and may not be copied,
+   modified or distributed except as expressly authorized under the terms
+   of the license contained in the file LICENSE in this distribution.
+
+   Refer to licensing information at http://www.artifex.com or contact
+   Artifex Software, Inc.,  39 Mesa Street, Suite 108A, San Francisco,
+   CA 94129, USA, for further information.
+*/
+
+/*
+    jbig2dec
+*/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include "os_types.h"
+
+#include <stdio.h>
+#include <ctype.h>
+
+#include "jbig2.h"
+#include "jbig2_priv.h"
+#include "jbig2_image.h"
+#include "jbig2_image_rw.h"
+
+/* take an image structure and write it to a file in pbm format */
+
+int
+jbig2_image_write_pbm_file(Jbig2Image *image, char *filename)
+{
+    FILE *out;
+    int code;
+
+    if ((out = fopen(filename, "wb")) == NULL) {
+        fprintf(stderr, "unable to open '%s' for writing", filename);
+        return 1;
+    }
+
+    code = jbig2_image_write_pbm(image, out);
+
+    fclose(out);
+    return (code);
+}
+
+/* write out an image struct as a pbm stream to an open file pointer */
+
+int
+jbig2_image_write_pbm(Jbig2Image *image, FILE *out)
+{
+    /* pbm header */
+    fprintf(out, "P4\n%d %d\n", image->width, image->height);
+
+    /* pbm format pads to a byte boundary, so we can
+       just write out the whole data buffer
+       NB: this assumes minimal stride for the width */
+    fwrite(image->data, 1, image->height * image->stride, out);
+
+    /* success */
+    return 0;
+}
+
+/* take an image from a file in pbm format */
+Jbig2Image *
+jbig2_image_read_pbm_file(Jbig2Ctx *ctx, char *filename)
+{
+    FILE *in;
+    Jbig2Image *image;
+
+    if ((in = fopen(filename, "rb")) == NULL) {
+        fprintf(stderr, "unable to open '%s' for reading\n", filename);
+        return NULL;
+    }
+
+    image = jbig2_image_read_pbm(ctx, in);
+
+    fclose(in);
+
+    return (image);
+}
+
+/* FIXME: should handle multi-image files */
+Jbig2Image *
+jbig2_image_read_pbm(Jbig2Ctx *ctx, FILE *in)
+{
+    int i, dim[2];
+    int done;
+    Jbig2Image *image;
+    int c;
+    char buf[32];
+
+    /* look for 'P4' magic */
+    while ((c = fgetc(in)) != 'P') {
+        if (feof(in))
+            return NULL;
+    }
+    if ((c = fgetc(in)) != '4') {
+        fprintf(stderr, "not a binary pbm file.\n");
+        return NULL;
+    }
+    /* read size. we must find two decimal numbers representing
+       the image dimensions. 'done' will index whether we're
+       looking for the width or the height and 'i' will be our
+       array index for copying strings into our buffer */
+    done = 0;
+    i = 0;
+    while (done < 2) {
+        c = fgetc(in);
+        /* skip whitespace */
+        if (c == ' ' || c == '\t' || c == '\r' || c == '\n')
+            continue;
+        /* skip comments */
+        if (c == '#') {
+            while ((c = fgetc(in)) != '\n');
+            continue;
+        }
+        /* report unexpected eof */
+        if (c == EOF) {
+            fprintf(stderr, "end-of-file parsing pbm header\n");
+            return NULL;
+        }
+        if (isdigit(c)) {
+            buf[i++] = c;
+            while (isdigit(c = fgetc(in))) {
+                if (i >= 32) {
+                    fprintf(stderr, "pbm parsing error\n");
+                    return NULL;
+                }
+                buf[i++] = c;
+            }
+            buf[i] = '\0';
+            if (sscanf(buf, "%d", &dim[done]) != 1) {
+                fprintf(stderr, "failed to read pbm image dimensions\n");
+                return NULL;
+            }
+            i = 0;
+            done++;
+        }
+    }
+    /* allocate image structure */
+    image = jbig2_image_new(ctx, dim[0], dim[1]);
+    if (image == NULL) {
+        fprintf(stderr, "failed to allocate %dx%d image for pbm file\n", dim[0], dim[1]);
+        return NULL;
+    }
+    /* the pbm data is byte-aligned, so we can
+       do a simple block read */
+    (void)fread(image->data, 1, image->height * image->stride, in);
+    if (feof(in)) {
+        fprintf(stderr, "unexpected end of pbm file.\n");
+        jbig2_image_release(ctx, image);
+        return NULL;
+    }
+    /* success */
+    return image;
+}