batch-convert-images

#!/bin/bash

QUALITY_TYPE="default"
RESIZE_OPTION=""
INPUT_TARGET=""

usage() {
    echo "Usage: $0 <output_format> [-q <quality>] [-r <resize>] [-i <input>]"
    echo "  <output_format>: Format to convert to (e.g., jpg, png, avif, webp)"
    echo "  -q <quality>:    Quality setting, e.g., 90 or lossless [Optional]"
    echo "  -r <resize>:     Resize geometry, e.g., 800x800 or 50% [Optional]"
    echo "  -i <input>:      Input file or directory (processes only this target) [Optional]"
    exit 1
}

check_dependencies() {
    if ! command -v mogrify &>/dev/null; then
        echo "Error: 'mogrify' command not found. Please install ImageMagick."
        exit 1
    fi
}

parse_arguments() {
    if [ $# -lt 1 ]; then
        usage
    fi

    OUTPUT_FORMAT=""
    while [[ $# -gt 0 ]]; do
        case "$1" in
            -q|--quality)
                shift
                if [ -z "$1" ]; then
                    echo "Error: -q requires a value (e.g. 90 or lossless)"
                    exit 1
                fi
                QUALITY_TYPE="$1"
                ;;
            -r|--resize)
                shift
                if [ -z "$1" ]; then
                    echo "Error: -r requires a resize value (e.g. 800x800, 800x, x800, or 50%)"
                    exit 1
                fi
                RESIZE_OPTION="-colorspace RGB -resize $1 -colorspace sRGB"
                ;;
            -i|--input)
                shift
                if [ -z "$1" ]; then
                    echo "Error: -i requires a file or directory as input"
                    exit 1
                fi
                INPUT_TARGET="$1"
                ;;
            -*)
                echo "Unknown option: $1"
                usage
                ;;
            *)
                if [ -z "$OUTPUT_FORMAT" ]; then
                    OUTPUT_FORMAT="$1"
                else
                    echo "Unexpected argument: $1"
                    usage
                fi
                ;;
        esac
        shift
    done

    if [[ -z "$OUTPUT_FORMAT" ]]; then
        echo "Error: No output format specified."
        usage
    fi
}

get_quality_flags() {
    local format="$1"
    local quality="$2"

    case "$quality" in
        lossless)
            case "$format" in
                webp) echo "-define webp:lossless=true" ;;
                avif) echo "-define avif:lossless=true" ;;
                png) echo "-define png:compression-level=9" ;;
                *) echo "" ;;
            esac
            ;;
        [0-9]*)
            case "$format" in
                jpg|heif|webp|avif) echo "-quality $quality" ;;
                png) echo "-define png:compression-level=9" ;;
                *) echo "" ;;
            esac
            ;;
        *) echo "" ;;
    esac
}

convert_images() {
    local input_formats=("$@")
    echo "Target format: $OUTPUT_FORMAT"
    echo "Input formats: ${input_formats[*]}"
    echo "Quality option: ${QUALITY_OPTION:-(default)}"
    echo "Resize option: ${RESIZE_OPTION:-(none)}"
    echo "Input target: ${INPUT_TARGET:-(all files)}"

    if [[ -n "$INPUT_TARGET" ]]; then
        if [[ -f "$INPUT_TARGET" ]]; then
            echo "Processing single file: $INPUT_TARGET"
            process_image "$INPUT_TARGET"
            return
        elif [[ -d "$INPUT_TARGET" ]]; then
            echo "Processing files in folder: $INPUT_TARGET"
            for img in "$INPUT_TARGET"/*; do
                if [[ -f "$img" ]]; then
                    process_image "$img"
                fi
            done
            return
        else
            echo "Error: Input target '$INPUT_TARGET' is neither a file nor a directory."
            exit 1
        fi
    fi

    # Process all image files if no input target is given
    for ext in "${input_formats[@]}"; do
        find . -type f -iname "*.$ext" -print0 | while IFS= read -r -d '' img; do
        process_image "$img"
    done
done
}

process_image() {
    local img="$1"
    local base_name
    local output_file

    base_name=$(basename "$img")
    output_file="${img%.*}.$OUTPUT_FORMAT"

    echo "Converting: $img -> $output_file"
    if convert "$img" $RESIZE_OPTION $QUALITY_OPTION "$output_file"; then
        echo "Converted: $img"
        rm -v "$img"
    else
        echo "Conversion failed for: $img" >> conversion_errors.log
    fi
}

main() {
    check_dependencies
    parse_arguments "$@"
    QUALITY_OPTION=$(get_quality_flags "$OUTPUT_FORMAT" "$QUALITY_TYPE")

    ALL_FORMATS=("jpg" "png" "webp" "heif" "avif")
    INPUT_FORMATS=()
    for ext in "${ALL_FORMATS[@]}"; do
        if [ "$ext" != "$OUTPUT_FORMAT" ]; then
            INPUT_FORMATS+=("$ext")
        fi
    done

    convert_images "${INPUT_FORMATS[@]}"
    echo "Conversion complete."
}

main "$@"