8. A computer system, comprising: a processor that is configured to execute machine-readable instructions; and a memory device that stores instruction modules that are executable by the processor, the instruction modules comprising: an image extraction module configured to electronically scan an image-based document to determine positions of word images in the image-based document and extract the word images from the image-based document; an image clustering module configured to group a subset of the word images into a word cluster based on a similarity of the word images, wherein the word images in the word cluster correspond to a same actual word; a translator configured to generate a character-encoded transcription for the word cluster based on the word images in the word cluster; and a document generator configured to add the character-encoded transcription to a text-based electronic document at locations corresponding to the positions of the word images in the image-based document.
8. A computer system, comprising: a processor that is configured to execute machine-readable instructions; and a memory device that stores instruction modules that are executable by the processor, the instruction modules comprising: an image extraction module configured to electronically scan an image-based document to determine positions of word images in the image-based document and extract the word images from the image-based document; an image clustering module configured to group a subset of the word images into a word cluster based on a similarity of the word images, wherein the word images in the word cluster correspond to a same actual word; a translator configured to generate a character-encoded transcription for the word cluster based on the word images in the word cluster; and a document generator configured to add the character-encoded transcription to a text-based electronic document at locations corresponding to the positions of the word images in the image-based document. 11. The computer system of claim 8 , wherein the translator is configured to generate an initial transcription for each word image in the word cluster and determine the character-encoded transcription based on the initial transcriptions.