77 lines
2.5 KiB
Bash
77 lines
2.5 KiB
Bash
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#!/bin/sh
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test -n "$2" || { echo "Usage: $0 <input.jpg> <output.jpg> [blurtimes]"; exit 0; }
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# --- Configuration ---
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# Define the size of the rectangle to crop (Width x Height)
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CROP_SIZE="128x128"
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CROP_WIDTH=128
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CROP_HEIGHT=128
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BLURTIMES=0
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test -n "$3" && BLURTIMES=$3
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# Input and Output filenames
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INPUT_FILE="$1" # <-- **CHANGE THIS** to your actual input file name
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OUTPUT_FILE="$2"
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# --- Pre-Check: Ensure the input file exists ---
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if [ ! -f "$INPUT_FILE" ]; then
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echo "🚨 Error: Input file '$INPUT_FILE' not found."
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echo "Please update the INPUT_FILE variable in the script."
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exit 1
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fi
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# --- 1. Get the dimensions of the input image ---
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# The 'identify' command returns image info; we use awk/cut to extract just the dimensions.
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# Example output format: "1920x1080"
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IMAGE_GEOMETRY=$(identify -format "%wx%h" "$INPUT_FILE")
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IMAGE_WIDTH=$(echo "$IMAGE_GEOMETRY" | cut -dx -f1)
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IMAGE_HEIGHT=$(echo "$IMAGE_GEOMETRY" | cut -dx -f2)
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echo "Input Image: $INPUT_FILE (${IMAGE_GEOMETRY})"
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echo "Crop Area: $CROP_SIZE"
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# --- 2. Calculate the maximum possible starting coordinates ---
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# To ensure the 16x16 crop doesn't go off the edge:
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# Max_X_Start = Image_Width - Crop_Width
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# Max_Y_Start = Image_Height - Crop_Height
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MAX_X=$((IMAGE_WIDTH - CROP_WIDTH))
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MAX_Y=$((IMAGE_HEIGHT - CROP_HEIGHT))
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# Check if the image is too small to crop
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if [ $MAX_X -lt 0 ] || [ $MAX_Y -lt 0 ]; then
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echo "🚨 Error: Image dimensions ($IMAGE_GEOMETRY) are smaller than the crop size ($CROP_SIZE)."
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exit 1
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fi
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# --- 3. Generate Random Coordinates ---
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# $RANDOM generates a pseudo-random integer (0 to 32767).
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# We use the modulo operator (%) to limit it to the required range (0 to MAX_X or MAX_Y).
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# Random X-coordinate (0 to MAX_X)
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RANDOM_X=$((RANDOM % (MAX_X + 1)))
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# Random Y-coordinate (0 to MAX_Y)
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RANDOM_Y=$((RANDOM % (MAX_Y + 1)))
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# --- 4. Assemble the ImageMagick Geometry String ---
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# The final geometry string is: <Width>x<Height>+<X_Offset>+<Y_Offset>
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CROP_GEOMETRY="${CROP_SIZE}+${RANDOM_X}+${RANDOM_Y}"
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echo "Random Start Coordinate: X=${RANDOM_X}, Y=${RANDOM_Y}"
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echo "ImageMagick Crop String: ${CROP_GEOMETRY}"
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# --- 5. Execute the ImageMagick Command ---
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# 'convert' is the core command.
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# -crop: Specifies the geometry string for cropping.
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# -quality 100: (Optional) Ensures best quality for the output JPEG.
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test -f $OUTPUT_FILE && rm $OUTPUT_FILE
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magick "$INPUT_FILE" \
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-crop "$CROP_GEOMETRY" \
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-blur 0x$BLURTIMES \
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-quality 100 \
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"$OUTPUT_FILE"
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echo "✅ thumbnail generated"
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