Ensure a nonnegative calculated Clevels value (#219)

samvera · Feb 8, 2023 · d676adf · d676adf
1 parent afc879e
commit d676adf
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diff --git a/lib/hydra/derivatives/processors/jpeg2k_image.rb b/lib/hydra/derivatives/processors/jpeg2k_image.rb
@@ -51,6 +51,7 @@ def calculate_recipe(args, quality, long_dim)
       end
 
       def level_count_for_size(long_dim)
+        return 0 if long_dim < 96
         levels = 0
         level_size = long_dim
         while level_size >= 96

diff --git a/spec/processors/jpeg2k_spec.rb b/spec/processors/jpeg2k_spec.rb
@@ -8,11 +8,16 @@
   let(:image) { MiniMagick::Image.open(filename) }
 
   describe "#calculate_recipe" do
-    it "calculates the number of levels from a size" do
+    it "calculates the number of levels from a size above the minimum threshold" do
       dim = 7200
       expect(described_class.level_count_for_size(dim)).to eq(6)
     end
 
+    it "calculates the number of levels as 0 from a size below the minimum threshold" do
+      dim = 50
+      expect(described_class.level_count_for_size(dim)).to eq(0)
+    end
+
     it "calculates the compression rates for each quality layer" do
       compression_num = 10
       layers = 8