modules/png (bytevector->png-image): New procedure

* modules/png.scm (bytevector->png-image): New procedure.
* tests/image.scm ("bytevector->png-image"): New test.

modules/png.scm

@@ -1,6 +1,6 @@
 ;;; png.scm -- GNU Guile PNG parser.
 
-;; Copyright (C) 2022 Artyom V. Poptsov <[email protected]>
+;; Copyright (C) 2022-2024 Artyom V. Poptsov <[email protected]>
 ;;
 ;; This program is free software: you can redistribute it and/or modify
 ;; it under the terms of the GNU General Public License as published by
@@ -27,13 +27,15 @@
 
 (define-module (png)
   #:use-module (oop goops)
+  #:use-module (rnrs io ports)
   #:use-module (png image)
   #:use-module (png fsm context)
   #:use-module (png fsm png-context)
   #:use-module (png fsm png-parser)
   #:use-module (png core chunk)
   #:use-module (png chunk-decoder)
   #:export (png->scm
+            bytevector->png-image
             scm->png))
 
 
@@ -58,6 +60,18 @@
             (png-compressed-image-decompress image remove-filter?)
             image)))))
 
+(define* (bytevector->png-image bv
+                                #:key
+                                (decompress? #t)
+                                (debug-mode? #f)
+                                (remove-filter? #t))
+  "Convert a bytevector @var{bv} to a PNG image. return the new image."
+  (with-input-from-port (open-bytevector-input-port bv)
+    (lambda ()
+      (png->scm #:decompress? decompress?
+                #:debug-mode? debug-mode?
+                #:remove-filter? remove-filter?))))
+
 (define* (scm->png image
                    #:optional
                    (port (current-output-port)))

tests/image.scm

@@ -3,6 +3,7 @@
              (ice-9 iconv)
              (rnrs bytevectors)
              (oop goops)
+             (png)
              (png image)
              (png core chunk)
              (png core chunk ihdr)
@@ -176,6 +177,14 @@
                  #:height     100)))
     (png-image->bytevector image)))
 
+(test-assert "bytevector->png-image"
+  (let ((image (make <png-image>
+                 #:color-type 2
+                 #:bit-depth  8
+                 #:width      10
+                 #:height     10)))
+    (bytevector->png-image (png-image->bytevector image))))
+
 
 (define exit-status (test-runner-fail-count (test-runner-current)))