Convert TIFF to CSV

A spreadsheet or analysis program may require pixel measurements or the contents of a scanned table as rows and columns. Converting the image means either exporting its pixel values or using OCR to recognize text; these produce different kinds of CSV data.

What TIFF stores

TIFF (Tagged Image File Format) stores raster images and is common in scanning, photography, publishing, and graphics workflows. It can hold high-resolution images, different color depths, and multiple pages, but visible text and table lines remain image pixels rather than editable cells.

What CSV stores

CSV is plain text arranged as records and fields, usually separated by commas. Spreadsheets, databases, and analysis tools can import it, but it cannot retain an image’s appearance, color profile, resolution, or page layout. Choose pixel export for numeric image data and OCR for text in a scan.

Convert pixel values

For a grayscale pixel matrix, use the free desktop program ImageJ. Open the TIFF with File → Open, choose Image → Type → 32-bit, then select File → Save As → Text Image. ImageJ saves pixel values as tab-delimited text. Open that file in LibreOffice Calc, choose the tab separator in the import dialog, then use File → Save As and select CSV as the file type.

ImageJ’s text export is a grayscale matrix, not separate RGB channels. Converting a color image to grayscale changes the data. For RGB values, this Python script writes one CSV row per pixel:

from PIL import Image
import csv

image = Image.open('input.tif').convert('RGB')
with open('output.csv', 'w', newline='', encoding='utf-8') as file:
    writer = csv.writer(file)
    writer.writerow(['x', 'y', 'R', 'G', 'B'])
    for y in range(image.height):
        for x in range(image.width):
            writer.writerow([x, y, *image.getpixel((x, y))])

Install Pillow with python -m pip install Pillow, save the script as tiff_to_csv.py, place input.tif beside it, and run python tiff_to_csv.py. This processes the first TIFF page and omits transparency; adapt it to process additional pages or retain alpha values if needed. A high-resolution image can produce a very large CSV.

Convert text in a scan

For a scanned table, use OCR rather than exporting pixels. The listed mini TIFF to CSV OCR Converter is the relevant offline option: open the TIFF, run recognition, review the detected text and table divisions, then export the result as CSV. OCR can miss characters or split and merge cells, especially with skewed, faint, or densely formatted tables; verify the exported rows against the image.

Compatibility limits

CSV has no standard way to represent TIFF pages, color channels as image data, or layout. ImageJ’s matrix export and the RGB script use different row structures, so confirm the expected columns and separators before importing into another program. For a multi-page TIFF, process each page separately or include a page identifier in the output.