This is to try and whittle down the bewildering choice between the number of products available. Any suggestions of relevant commercial or public domain systems are greatly appreciated. OCR run-time library routine which can preferably be linked with a C program or otherwise invoked from a C program. No manual intervention possible. Contrast between characters and background may vary within the image.
Characters are normally light on a dark background, but can also be dark on light.
Particular configuration not known in advance. Typefaces may vary within the image, but will not be too strange, i.e. normal latin alphanumeric characters. Although it would be good if the software was trainable to learn logos. Particular orientation of a given image is not known in advance. Computer vision system is being sold as a commercial product.