         return context.image
     }()
     
-    func testPng1() {
+    func testPng1() throws {
         
         guard let data = sample1.pngRepresentation() else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample1.pixels, result.pixels)
     }
     
-    func testPng2() {
+    func testPng2() throws {
         
         guard let data = sample2.pngRepresentation() else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample2.pixels, result.pixels)
     }
     
-    func testPng3() {
+    func testPng3() throws {
         
         guard let data = sample3.pngRepresentation() else { XCTFail(); return }
         
-        guard let result = try? Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray) else { XCTFail(); return }
+        let result = try Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray)
         
         XCTAssertEqual(sample3.pixels, result.pixels)
     }
     
-    func testPng4() {
+    func testPng4() throws {
         
         guard let data = sample4.pngRepresentation() else { XCTFail(); return }
         
-        guard let result = try? Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray) else { XCTFail(); return }
+        let result = try Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray)
         
         XCTAssertEqual(sample4.pixels, result.pixels)
     }
     
-    func testPng1Interlaced() {
+    func testPng1Interlaced() throws {
         
         guard let data = sample1.pngRepresentation(interlaced: true) else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample1.pixels, result.pixels)
     }
     
-    func testPng2Interlaced() {
+    func testPng2Interlaced() throws {
         
         guard let data = sample2.pngRepresentation(interlaced: true) else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample2.pixels, result.pixels)
     }
     
-    func testPng3Interlaced() {
+    func testPng3Interlaced() throws {
         
         guard let data = sample3.pngRepresentation(interlaced: true) else { XCTFail(); return }
         
-        guard let result = try? Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray) else { XCTFail(); return }
+        let result = try Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray)
         
         XCTAssertEqual(sample3.pixels, result.pixels)
     }
     
-    func testPng4Interlaced() {
+    func testPng4Interlaced() throws {
         
         guard let data = sample4.pngRepresentation(interlaced: true) else { XCTFail(); return }
         
-        guard let result = try? Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray) else { XCTFail(); return }
+        let result = try Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray)
         
         XCTAssertEqual(sample4.pixels, result.pixels)
     }
     
-    func testBmp1() {
+    func testBmp1() throws {
         
         guard let data = sample1.representation(using: .bmp, properties: [:]) else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample1.pixels, result.pixels)
     }
     
-    func testBmp2() {
+    func testBmp2() throws {
         
         guard let data = sample2.representation(using: .bmp, properties: [:]) else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample2.pixels, result.pixels)
     }
     
-    func testTiff1() {
+    func testTiff1() throws {
         
         guard let data = sample1.tiffRepresentation() else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample1.pixels, result.pixels)
     }
     
-    func testTiff2() {
+    func testTiff2() throws {
         
         guard let data = sample2.tiffRepresentation() else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample2.pixels, result.pixels)
     }
     
-    func testTiff3() {
+    func testTiff3() throws {
         
         guard let data = sample3.tiffRepresentation() else { XCTFail(); return }
         
-        guard let result = try? Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray) else { XCTFail(); return }
+        let result = try Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray)
         
         XCTAssertEqual(sample3.pixels, result.pixels)
     }
     
-    func testTiff4() {
+    func testTiff4() throws {
         
         guard let data = sample4.tiffRepresentation() else { XCTFail(); return }
         
-        guard let result = try? Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray) else { XCTFail(); return }
+        let result = try Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray)
         
         XCTAssertEqual(sample4.pixels, result.pixels)
     }
     
-    func testTiff5() {
+    func testTiff5() throws {
         
         guard let data = Image<Float32ColorPixel<LabColorModel>>(image: sample1, colorSpace: .default).tiffRepresentation() else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample1.pixels, result.pixels)
     }
     
-    func testTiff6() {
+    func testTiff6() throws {
         
         guard let data = Image<Float32ColorPixel<LabColorModel>>(image: sample2, colorSpace: .default).tiffRepresentation() else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample2.pixels, result.pixels)
     }
     
-    func testTiff1PackBits() {
+    func testTiff1PackBits() throws {
         
         guard let data = sample1.tiffRepresentation(compression: .packBits) else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample1.pixels, result.pixels)
     }
     
-    func testTiff2PackBits() {
+    func testTiff2PackBits() throws {
         
         guard let data = sample2.tiffRepresentation(compression: .packBits) else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample2.pixels, result.pixels)
     }
     
-    func testTiff3PackBits() {
+    func testTiff3PackBits() throws {
         
         guard let data = sample3.tiffRepresentation(compression: .packBits) else { XCTFail(); return }
         
-        guard let result = try? Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray) else { XCTFail(); return }
+        let result = try Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray)
         
         XCTAssertEqual(sample3.pixels, result.pixels)
     }
     
-    func testTiff4PackBits() {
+    func testTiff4PackBits() throws {
         
         guard let data = sample4.tiffRepresentation(compression: .packBits) else { XCTFail(); return }
         
-        guard let result = try? Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray) else { XCTFail(); return }
+        let result = try Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray)
         
         XCTAssertEqual(sample4.pixels, result.pixels)
     }
     
-    func testTiff5PackBits() {
+    func testTiff5PackBits() throws {
         
         guard let data = Image<Float32ColorPixel<LabColorModel>>(image: sample1, colorSpace: .default).tiffRepresentation(compression: .packBits) else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample1.pixels, result.pixels)
     }
     
-    func testTiff6PackBits() {
+    func testTiff6PackBits() throws {
         
         guard let data = Image<Float32ColorPixel<LabColorModel>>(image: sample2, colorSpace: .default).tiffRepresentation(compression: .packBits) else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample2.pixels, result.pixels)
     }
     
-    func testTiff1LZW() {
+    func testTiff1LZW() throws {
         
         guard let data = sample1.tiffRepresentation(compression: .lzw) else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample1.pixels, result.pixels)
     }
     
-    func testTiff2LZW() {
+    func testTiff2LZW() throws {
         
         guard let data = sample2.tiffRepresentation(compression: .lzw) else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample2.pixels, result.pixels)
     }
     
-    func testTiff3LZW() {
+    func testTiff3LZW() throws {
         
         guard let data = sample3.tiffRepresentation(compression: .lzw) else { XCTFail(); return }
         
-        guard let result = try? Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray) else { XCTFail(); return }
+        let result = try Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray)
         
         XCTAssertEqual(sample3.pixels, result.pixels)
     }
     
-    func testTiff4LZW() {
+    func testTiff4LZW() throws {
         
         guard let data = sample4.tiffRepresentation(compression: .lzw) else { XCTFail(); return }
         
-        guard let result = try? Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray) else { XCTFail(); return }
+        let result = try Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray)
         
         XCTAssertEqual(sample4.pixels, result.pixels)
     }
     
-    func testTiff5LZW() {
+    func testTiff5LZW() throws {
         
         guard let data = Image<Float32ColorPixel<LabColorModel>>(image: sample1, colorSpace: .default).tiffRepresentation(compression: .lzw) else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample1.pixels, result.pixels)
     }
     
-    func testTiff6LZW() {
+    func testTiff6LZW() throws {
         
         guard let data = Image<Float32ColorPixel<LabColorModel>>(image: sample2, colorSpace: .default).tiffRepresentation(compression: .lzw) else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample2.pixels, result.pixels)
     }
     
-    func testTiff1Deflate() {
+    func testTiff1Deflate() throws {
         
         guard let data = sample1.tiffRepresentation(compression: .deflate) else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample1.pixels, result.pixels)
     }
     
-    func testTiff2Deflate() {
+    func testTiff2Deflate() throws {
         
         guard let data = sample2.tiffRepresentation(compression: .deflate) else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample2.pixels, result.pixels)
     }
     
-    func testTiff3Deflate() {
+    func testTiff3Deflate() throws {
         
         guard let data = sample3.tiffRepresentation(compression: .deflate) else { XCTFail(); return }
         
-        guard let result = try? Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray) else { XCTFail(); return }
+        let result = try Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray)
         
         XCTAssertEqual(sample3.pixels, result.pixels)
     }
     
-    func testTiff4Deflate() {
+    func testTiff4Deflate() throws {
         
         guard let data = sample4.tiffRepresentation(compression: .deflate) else { XCTFail(); return }
         
-        guard let result = try? Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray) else { XCTFail(); return }
+        let result = try Image<Gray16ColorPixel>(image: AnyImage(data: data), colorSpace: .genericGamma22Gray)
         
         XCTAssertEqual(sample4.pixels, result.pixels)
     }
     
-    func testTiff5Deflate() {
+    func testTiff5Deflate() throws {
         
         guard let data = Image<Float32ColorPixel<LabColorModel>>(image: sample1, colorSpace: .default).tiffRepresentation(compression: .deflate) else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample1.pixels, result.pixels)
     }
     
-    func testTiff6Deflate() {
+    func testTiff6Deflate() throws {
         
         guard let data = Image<Float32ColorPixel<LabColorModel>>(image: sample2, colorSpace: .default).tiffRepresentation(compression: .deflate) else { XCTFail(); return }
         
-        guard let result = try? Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB) else { XCTFail(); return }
+        let result = try Image<ARGB32ColorPixel>(image: AnyImage(data: data), colorSpace: .sRGB)
         
         XCTAssertEqual(sample2.pixels, result.pixels)
     }
     
-    func testPngSuite() {
-        
-        guard let images = try? FileManager.default.contentsOfDirectory(at: images_dir.appendingPathComponent("png_test_suite"), includingPropertiesForKeys: nil, options: []) else { XCTFail(); return }
+    func testPngSuite() throws {
+        
+        let images = try FileManager.default.contentsOfDirectory(at: images_dir.appendingPathComponent("png_test_suite"), includingPropertiesForKeys: nil, options: [])
         
         for image in images where image.pathExtension == "png" {
             
-            guard let png_image = try? AnyImage(contentsOf: image) else { XCTFail(); return }
-            guard let tiff_image = try? AnyImage(contentsOf: image.deletingPathExtension().appendingPathExtension("tif")) else { XCTFail(); return }
+            let png_image = try AnyImage(contentsOf: image)
+            let tiff_image = try AnyImage(contentsOf: image.deletingPathExtension().appendingPathExtension("tif"))
             
             XCTAssertEqual(png_image.width, tiff_image.width)
             XCTAssertEqual(png_image.height, tiff_image.height)

            RawBitmap.Channel(index: 0, format: .unsigned, endianness: .big, bitRange: 1..<6),
            RawBitmap.Channel(index: 1, format: .unsigned, endianness: .big, bitRange: 6..<11),
            RawBitmap.Channel(index: 2, format: .unsigned, endianness: .big, bitRange: 11..<16),
            ], data: data)
        
        let image = AnyImage(width: width, height: height, colorSpace: AnyColorSpace.sRGB, bitmaps: [bitmap], premultiplied: false, fileBacked: false).base as? Image<RGBA32ColorPixel>
        

            RawBitmap.Channel(index: 0, format: .unsigned, endianness: .big, bitRange: 1..<6),
            RawBitmap.Channel(index: 1, format: .unsigned, endianness: .big, bitRange: 6..<11),
            RawBitmap.Channel(index: 2, format: .unsigned, endianness: .big, bitRange: 11..<16),
        ], data: data)
        
        let image = AnyImage(width: width, height: height, colorSpace: AnyColorSpace.sRGB, bitmaps: [bitmap], premultiplied: false, fileBacked: false).base as? Image<RGBA32ColorPixel>
        
